This is gcal.info, produced by makeinfo version 4.0 from gcal.texi.

INFO-DIR-SECTION GNU packages
START-INFO-DIR-ENTRY
* Gcal: (gcal).                       GNU calendar program.
* Tcal: (gcal)Invoking tcal.          Run Gcal with tomorrow's date.
* Txt2gcal: (gcal)Invoking txt2gcal.  Calendar text to resource file.
* Gcal2txt: (gcal)Invoking gcal2txt.  Calendar resource to text file.
END-INFO-DIR-ENTRY

  This file documents Gcal, a program for calculating and printing
calendars.

  Copyright (c) 1994, 95, 96, 1997, 2000 Thomas Esken

  This edition is for Gcal version 3.01.

  Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.

  Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the
entire resulting derived work is distributed under the terms of a
permission notice identical to this one.

  Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that this permission notice may be stated in a
translation approved by the Free Software Foundation.

  Any suggestions, improvements, extensions, bug reports, donations,
proposals for contract work, and so forth are welcome!  Please send
them directly to my eMail address <esken@gmx.net>.  If you like my
work, I'd appreciate a postcard from you!

------------------------oOO      \\\_''/      OOo---------------------------
Thomas Esken               O     (/o-o\)     O  eMail: esken@gmx.net
Im Hagenfeld 84                 ((  ^  ))       Phone: +49 251 232585
D-48147 Muenster; Germany    \____) ~ (____/    MotD : 2old2live, 2young2die


File: gcal.info,  Node: Biorhythm,  Next: Difference value,  Prev: Moon phase,  Up: Replacements with date argument

Biorhythm `%?[DATE]' special texts
..................................

  Gcal is able to create a "biorhythm" for any specified date of birth.
The created text shows the three standard biorhythm cycles, and that
are the 28 day emotional cycle, the 33 day intellectual cycle, and the
23 day physical cycle.  The emotional cycle governs sensibility,
nerves, moodiness, and creative ability.  The intellectual cycle
reflects intelligence, memory, mental alertness, and reasoning power.
The physical cycle represents physical strength, endurance, energy and
resistance.  All cycles start in the zero point at the date of birth
and swing like sine curves between their positive and negative maximum
values.  The periods above the zero point show the days of full
vitality and efficiency while the periods below the zero point indicate
days of reduced efficiency.  The biorhythm is implemented for
entertaining purposes only!  It is up to the user to interpret the
biorhythm texts.

  Gcal counts "critical" days, "positive" likewise "negative" days.
Critical days are those days in which one or more of the biological
cycles crosses the zero point.  At that time, one's system is said to
be in a state of flux and it may be desirable to exhibit caution.
Positive days are those days in which one or more of the biological
cycles have a positive maximum value.  At that time, one's system is
said to be in a raised state.  Negative days are those days in which
one or more of the biological cycles have a negative maximum value.  At
that time, one's system is said to be in a lessen state.

  The following biorhythm `%?[DATE]' special texts are respected:

`%,[DATE]'
     Is replaced by the *biorhythm text* of the current day of year,
     e.g.:

          The text `%,19620921' will be expanded to
          ==> `1! 0+ 0- , Emo=+022%- Int=-091%+ Phy=-014%-', in case
          the actual system date is the 12th December 1996.

     The preceding example shows the calculated biorhythm expressed as
     a series of values for a person born in 1962, September 21st.  The
     constructed text consists of two parts, and that is on the one
     hand a triplet of total values which indicate the critical,
     positive and negative day.  And on the other hand a triplet of
     values which indicate the emotional, intellectual and physical
     cycle.

     In the first triplet of total values, a `!' suffix means a
     critical day, a `+' indicates a positive day, and a `-' suffix
     marks a negative day.

     In the second triplet of values, each single cycle percent value
     consists of a leading positive or negative sign that tells
     something about the distance of this value to the zero point, and
     a trailing character that tells something about the state of each
     cycle.  A trailing `+' character marks a waxing phase, a `-'
     suffix means a waning phase, and a `@' indicates the maximum value
     of a phase.

`%;[DATE]'
     Is replaced by the *biorhythm text graphics* of the current day of
     year, e.g.:

          The text `%;19620921' will be expanded to
          ==> `0-  I               P 1   E                +0', in case
          the actual system date is the 12th December 1996.

     The preceding example shows the calculated biorhythm expressed as
     a text graphics line for a person born in 1962, September 21st.
     The constructed line is a bar with a negative and positive axis of
     adjustable length (*note Fixed date option
     `--biorhythm-axis=NUMBER': x-biorhythm-axis.), which left margin
     is represented by the total value of the negative days (the `0-'
     in this case), and which right margin is represented by the total
     value of the positive days (the `+0' in this case).  The zero
     point of the co-ordinate is represented by the total value of the
     critical days, which is the `1' in this case.  The emotional,
     intellectual and the physical phase value is accordingly placed in
     scaled manner on this bar, and that by using the initial letter of
     the cycle in each case (`E', `I' and `P').  Coincidental phase
     values are marked by a `@' character.


File: gcal.info,  Node: Difference value,  Prev: Biorhythm,  Up: Replacements with date argument

Difference value `%[FORMAT]?[DATE]' special texts
.................................................

  The following difference value `%[FORMAT]?[DATE]' special texts are
respected:

`%yDATE'
     Is replaced by a *year difference value*, e.g.:

          The text `Sylvester 1912 is %y1912  years ago' will be
          expanded to
          ==> `Sylvester 1912 is -82 years ago', in case the year of
          the actual system date is 1994.

`%B[DATE]'
     Is replaced by an *age value*, e.g.:

          The text `My %B1962  birthday%i1952#2062' will be expanded to
          ==> `My 32 birthday', in case the year of the actual system
          date is 1994.

     Those age values are only displayed, if the computation of an age
     value is greater zero.  The fixed date warning in preceding example
     is displayed only in case the current year is greater than 1952
     and less than 2062.

`%>1&*B[DATE]'
     Is replaced by an *age value* with trailing Ordinal Number suffix,
     e.g.:

          The text `My %>1&*B1962  birthday%i1952#2062' will be
          expanded to
          ==> `My 32nd birthday', in case the year of the actual system
          date is 1994.

     Those age values are only displayed, if the computation of an age
     value is greater zero.  The fixed date warning in preceding example
     is displayed only in case the current year is greater than 1952
     and less than 2062.


File: gcal.info,  Node: Replacements with other argument,  Next: Replacements without any argument,  Prev: Replacements with date argument,  Up: Replacements

Replacements with other argument `%[FORMAT]?[ARGUMENT]' special texts
---------------------------------------------------------------------

* Menu:

* Actual clocktime::
* Textual date::
* Julian day number::
* Geographical distance and course angle::
* Sun data::
* Moon data::
* Contents of Environment variable::

  Apart from different representations of the actual system time, a
fixed format date text can be created.  Moreover, it is possible to
produce a day number, which bears the Julian date as base date and
which can be deferred if needed.  Furthermore, the approximate distance
and the course angle between two geographic point locations, and
different Sun and Moon oriented data and times for at pleasure any
geographical location can be created.  It is also possible to display
the contents of environment variables in the fixed date text.

  For the ARGUMENT these `%?[ARGUMENT]' special texts may have, no
special rules concerning definite omission values are valid.


File: gcal.info,  Node: Actual clocktime,  Next: Textual date,  Prev: Replacements with other argument,  Up: Replacements with other argument

Actual clocktime `%[FORMAT]?[ARGUMENT]' special texts
.....................................................

  Gcal is able to represent the actual clocktime as local/zone time and
as Universal time (UTC/GMT), and additionally the RFC-822(1) (*note
Actual clocktime-Footnote-1::) style numerical Universal time timezone
offset value and the actual numerical local time timezone offset value.
*Note Actual local time `%t[ARGUMENT]' special text:
x-Actual-local-time, for the detailed description of all components of
the ARGUMENT, which may trail the actual clocktime
`%[FORMAT]?[ARGUMENT]' special texts.  All actual clocktime
`%[FORMAT]?[ARGUMENT]' special texts *must* always be trailed by a
_whitespace_ character which is removed in output!  The following
actual clocktime `%[FORMAT]?[ARGUMENT]' special texts are respected:

`%t[ARGUMENT]'
     `%t[*][[+|-]MMMM|HH:[MM]]' references the *actual local time*,
     which is displayed by using the `HH:MM' output format, e.g.:

          The text `Local time: %t  --> Dentist at 10:00' will be
          expanded to
          ==> `Local time: 07:32 --> Dentist at 10:00', in case the
          actual local time value is 07:32 o'clock (`HH:MM').

     If only `%t' is specified, the local time value will implicitly be
     displayed by using the _24-hours_ format.  For displaying using the
     _12-hours_ format, add a `*' character directly behind `%t', e.g.
     `%t*'.

     A displacement value may trail the `%t' special text, which has to
     be specified either by using the `[+|-]MMMM' format or the
     `[+|-]HH:[MM]' format.  `[+|-]MMMM' adds respectively subtracts
     the specified amount of minutes MMMM from the local time value
     (range `0...9999'), while `[+|-]HH:[MM]' adds respectively
     subtracts the given amount of hours HH (range `0...99') and
     minutes MM (range `0...59') from the local time value.  The
     displacement value is always added to the local time value in case
     it is specified without a `+|-' sign.  In case Gcal is unable to
     compute the actual local time in `HH:MM' format by reason of a
     misspecified ARGUMENT, a `??:??' text will be created instead of
     the actual local time in `HH:MM' format.

          The text `Local time: %t-3:  --> Dentist at 10:00' will be
          expanded to
          ==> `Local time: 04:32 --> Dentist at 10:00', in case the
          actual local time value is 07:32 o'clock (`HH:MM').

`%[FORMAT]'[ARGUMENT]'
     `%[FORMAT]'[[+|-]MMMM|HH:[MM]]' references the *actual local time
     in minutes since midnight*, which is displayed by using the
     M[M...] output format, e.g.:

          The text `Local time: %'  --> Dentist at 10:00' will be
          expanded to
          ==> `Local time: 452 --> Dentist at 10:00', in case the
          actual local time value is 07:32 o'clock (`HH:MM').

     In case Gcal is unable to compute the actual local time in M[M...]
     format by reason of a misspecified ARGUMENT, a `??' text will be
     created instead of the actual local time in M[M...] format.

`%[FORMAT]_[ARGUMENT]'
     `%[FORMAT]_[*][[+|-]MMMM|HH:[MM]]' references the *actual local
     time hour*, which is displayed by using the H[H...] output format,
     e.g.:

          The text `Local time hour: %_-1:' will be expanded to
          ==> `Local time hour: 6' in case the actual local time value
          is 07:32 o'clock (`HH:MM').

     In case Gcal is unable to compute the actual local time hour by
     reason of a misspecified ARGUMENT, a `??' text will be created
     instead of the actual local time hour H[H...].

`%[FORMAT]?[ARGUMENT]'
     `%[FORMAT]?[[+|-]MMMM|HH:[MM]]' references the *actual local time
     minute*, which is displayed by using the M[M...] output format,
     e.g.:

          The text `Local time minute: %>04*?+:2' will be expanded to
          ==> `Local time minute: 0034' in case the actual local time
          value is 07:32 o'clock (`HH:MM').

     In case Gcal is unable to compute the actual local time minute by
     reason of a misspecified ARGUMENT, a `??' text will be created
     instead of the actual local time minute M[M...].

`%[FORMAT]{[ARGUMENT]'
     `%[FORMAT]{[[+|-]MMMM|HH:[MM]]' references the *actual local time
     12-hour format suffix*, which is displayed as `am|pm', e.g.:

          The text `Local time suffix: %{' will be expanded to
          ==> `Local time suffix: am' in case the actual local time
          value is 07:32 o'clock (`HH:MM').

     In case Gcal is unable to compute the actual local time 12-hour
     format suffix by reason of a misspecified ARGUMENT, a `??' text
     will be created instead of the actual local time 12-hour format
     suffix `am|pm'.

`%@[ARGUMENT]'
     `%@[*][[+|-]MMMM|HH:[MM]]' references the *actual Universal time*
     (UTC/GMT), which is displayed by using the `HH:MM/DATE' output
     format, e.g.:

          The text `Universal time: %@*-3.' will be expanded to
          ==> `Universal time: 03:32am/15-Feb-1999', in case the actual
          date is the 15th February 1999 and the actual Universal time
          value is 06:32 o'clock (`HH:MM').

     In case Gcal is unable to compute the actual Universal time in
     `HH:MM/DATE' format by reason of a misspecified ARGUMENT, a
     `??:??/??-???-????' text will be created instead of the actual
     Universal time in `HH:MM/DATE' format.

`%[FORMAT]`[ARGUMENT]'
     `%[FORMAT]`[[+|-]MMMM|HH:[MM]]' references the *actual Universal
     time in minutes since midnight*, which is displayed by using the
     `M[M...]/DATE' output format, e.g.:

          The text `Universal time: %>06*`-3:' will be expanded to
          ==> `Universal time: 000212/15-Feb-1999' in case the actual
          date is the 15th February 1999 and the actual Universal time
          value is 06:32 o'clock (`HH:MM').

     In case Gcal is unable to compute the actual Universal time in
     `M[M...]/DATE' format by reason of a misspecified ARGUMENT, a
     `??/??-???-????' text will be created instead of the actual
     Universal time in `M[M...]/DATE' format.

`%[FORMAT].[ARGUMENT]'
     `%[FORMAT].[*][[+|-]MMMM|HH:[MM]]' references the *actual
     Universal time hour*, which is displayed by using the H[H...]
     output format, e.g.:

          The text `Universal time hour: %.-1:' will be expanded to
          ==> `Universal time hour: 5' in case the actual Universal
          time value is 06:32 o'clock (`HH:MM').

     In case Gcal is unable to compute the actual Universal time hour
     by reason of a misspecified ARGUMENT, a `??' text will be created
     instead of the actual Universal time hour H[H...].

`%[FORMAT]/[ARGUMENT]'
     `%[FORMAT]/[[+|-]MMMM|HH:[MM]]' references the *actual Universal
     time minute*, which is displayed by using the M[M...] output
     format, e.g.:

          The text `Universal time minute: %>04*/+:2' will be expanded
          to
          ==> `Universal time minute: 0034' in case the actual
          Universal time value is 06:32 o'clock (`HH:MM').

     In case Gcal is unable to compute the actual Universal time minute
     by reason of a misspecified ARGUMENT, a `??' text will be created
     instead of the actual Universal time minute M[M...].

`%[FORMAT]}[ARGUMENT]'
     `%[FORMAT]}[[+|-]MMMM|HH:[MM]]' references the *actual Universal
     time 12-hour format suffix*, which is displayed as `am|pm', e.g.:

          The text `Universal time suffix: %>1w*}+10:' will be expanded
          to
          ==> `Universal time suffix: Pm' in case the actual Universal
          time value is 06:32 o'clock (`HH:MM').

     In case Gcal is unable to compute the actual Universal time
     12-hour format suffix by reason of a misspecified ARGUMENT, a `??'
     text will be created instead of the actual Universal time 12-hour
     format suffix `am|pm'.

`%"[ARGUMENT]'
     `%"[[+|-]MMMM|HH:[MM]]' references the RFC-822 style *numerical
     Universal time timezone offset value*, which is displayed by using
     the `+|-HHMM' output format, e.g.:

          The text `Universal time timezone offset value: %"-90' will
          be expanded to
          ==> `Universal time timezone offset value: -0130', at which
          calculations are always based on the timezone of the
          Universal time UTC/GMT.

     In case Gcal is unable to compute the numerical Universal time
     timezone offset value by reason of a misspecified ARGUMENT, a
     `+????' text will be created instead of the numerical Universal
     time timezone offset value `+|-HHMM'.

`%=[ARGUMENT]'
     `%=[[+|-]MMMM|HH:[MM]]' references the RFC-822 style *actual
     numerical local time timezone offset value*, which is displayed by
     using the `+|-HHMM' output format, e.g.:

          The text `Local time timezone offset value CET: %=-10' will
          be expanded to
          ==> `Local time timezone offset value CET: +0050', in case
          the actual timezone is equal the Central European (winter)time
          CEWT/CET (`+HHMM').  Calculations are always based on the
          timezone of the local time.

     In case Gcal is unable to compute the actual numerical local time
     timezone offset value by reason of a misspecified ARGUMENT, a
     `+????' text will be created instead of the actual numerical local
     time timezone offset value `+|-HHMM'.


File: gcal.info,  Node: Actual clocktime-Footnotes,  Up: Actual clocktime

  (1) RFC is the abbreviation of `Request for Comments'.


File: gcal.info,  Node: Textual date,  Next: Julian day number,  Prev: Actual clocktime,  Up: Replacements with other argument

Textual date `%n[ARGUMENT]' special text
........................................

  `%n[[+|-]N]' references the current respectively queried *day number*
relative to the current date `+/-' N days and is replaced by a *date
text* by using the fixed `%>02*D-%>3#U-%>04*Y' format, e.g.:

     The resource file line `1962Sep21 10000 days old: %n+10000' will
     be expanded to
     ==> `10000 days old: 06-Feb-1990', in case you call Gcal with the
     simple `-c' option and the command `sep 1962' (*note Single
     command `MM YYYY': x-mm-yyyy.).


File: gcal.info,  Node: Julian day number,  Next: Geographical distance and course angle,  Prev: Textual date,  Up: Replacements with other argument

Julian day number `%[FORMAT]j[ARGUMENT]' special text
.....................................................

  `%[FORMAT]j[[+|-]N]' references the current respectively queried
*Julian day number* relative to the actual system date (==today).  This
day number is based on the date 1st January 4713 BCE --which is the
starting day zero of a consecutive day counting used in astronomical
computations-- and is known as the Julian Date (J.D.).  The real zero
of this date is at 12 o'clock Universal time (UTC/GMT); the day does
not change at midnight, but at noon Universal time.  Here, Gcal does
not evaluate the timezone returned by the systems date function.  For
that reason, this day number is represented without a time fraction on
the supposition that the day has already changed at noon.  If you do
not like the feature that the day displayed has already changed at
noon, you can decrease the resulting Julian day number of that special
text always by one, e.g. `%j-1'.

  For example:

     The resource file line `0 Julian day %j since 01-Jan-4713 BCE'
     will be expanded to
     ==> `Julian day 2437929 since 01-Jan-4713 BCE', in case you call
     Gcal with the `-c %19620921' option and no command.

  If the `%[FORMAT]j' text is directly trailed by an unsigned number,
this number is always subtracted from the real Julian day number.  So
you are able to work with any quantities referenced, e.g.:

     The resource file line `0 Julian day %j2415021 since 01-Jan-1900'
     will be expanded to
     ==> `Julian day 4 since 01-Jan-1900', in case you call Gcal with
     the `-c %19000105' option and no command.


File: gcal.info,  Node: Geographical distance and course angle,  Next: Sun data,  Prev: Julian day number,  Up: Replacements with other argument

Geographical distance and course angle `%[FORMAT]bARGUMENT' special text
........................................................................

`%[FORMAT]b[*][MODE]ISO-6709:1983-CO-ORDINATE-1/ISO-6709:1983-CO-ORDINATE-2'
references either the approximate *air line distance* or the
approximate *course angle (true track)*(1) (*note Geographical distance
and course angle-Footnote-1::) between any of two geographic point
locations.  The selection, which value has to be calculated by using
this special text is done by specifying the MODE part of the preceding
argument.  Actually, exactly three different modes can be used that are
represented by the `0'...`2' characters:

*Mode*      *Description*

`0'         Calculates the air line distance between
            ISO-6709:1983-CO-ORDINATE-1 and ISO-6709:1983-CO-ORDINATE-2.
            The calculated air line distance value is displayed in
            kilometers by default.  A `*' character directly before this
            mode character causes Gcal to display the distance value for
            another quantity, and that in "statute miles"; where one
            statute mile is equal to 1.609344 kilometer.  If Gcal is
            unable to compute the approximate distance between the two
            geographic point locations by reason of a misspecified
            ARGUMENT, a `??' text will be created instead of the
            distance value.

`1'         Calculates the course angle (true track) between
            ISO-6709:1983-CO-ORDINATE-1 and ISO-6709:1983-CO-ORDINATE-2.
            The calculated course angle value is displayed in degrees
            and arcminutes by default.  The course angle is measured
            clockwise relative to the geographic, true North (not the
            magnetic North as shown by a compass), where angle values
            for the North direction are both denoted as 0 degree and 360
            degree.  A `*' character directly before this mode character
            causes Gcal to display the course angle value using another
            style; and that in decimal degrees.  If Gcal is unable to
            compute the approximate course angle between the two
            geographic point locations by reason of a misspecified
            ARGUMENT, a `???d??'' text will be created instead of the
            course angle value.

`2'         Like mode `1', but the course angle (true track) between
            ISO-6709:1983-CO-ORDINATE-2 and ISO-6709:1983-CO-ORDINATE-1
            is calculated.

  If no MODE is given, Gcal automatically uses that mode, which is
enabled by the mode character `0'.  If a mode character is given that
is not according to one of the `0'...`2' characters, Gcal also
automatically uses that mode, which is enabled by the mode character
`0'.

  After the optional style and mode characters, the latitude and
longitude of the geographic co-ordinates follows, for which the
calculations must be made.  They must be conform the ISO-6709:1983
standard representation of latitude and longitude for geographic point
locations.  The two co-ordinates have to be separated by a `/'
termination character from each other.

  *Note Arguments of the Sun oriented special texts: x-Sun-arguments,
for the detailed description of the components of the ISO-6709:1983
standard representation of latitude and longitude for geographic point
locations.

  For example:

     The text `Distance Paris-Tokyo: %b+4852+00220/+3542+13946 km' will
     be expanded to
     ==> `Distance Paris-Tokyo: 9746km'.

     The text `Distance Paris-Tokyo: %b*0+4852+00220/+3542+13946 ms'
     will be expanded to
     ==> `Distance Paris-Tokyo: 6056ms'.

     The text `Course angle Paris-Tokyo: %b1+4852+00220/+3542+13946'
     will be expanded to
     ==> `Course angle Paris-Tokyo: 033d22''.

     The text `Course angle Tokyo-Paris: %b*2+4852+00220/+3542+13946'
     will be expanded to
     ==> `Course angle Tokyo-Paris: 333.548'.

  While praying, people of Islamic faith always turn their heads into
the direction of Makkah, Saudi-Arabia.  Now by means of Gcal, these
people can easily find out for their respective location, where they
have to turn to, and that by:

     %b1ISO-6709:1983-CO-ORDINATE-1/+212516+0394929

where ISO-6709:1983-CO-ORDINATE-1 is simply replaced by the co-ordinate
of the respective location.

  *Note Fixed date option `--precise': x-precise, how to obtain a more
precise representation of the values that are caused by this special
text.

  This special text *must* always be trailed by a _whitespace_
character which is removed in output!


File: gcal.info,  Node: Geographical distance and course angle-Footnotes,  Up: Geographical distance and course angle

  (1) The course angle gives the direction, which is the vertex of a
great circles arc ("Orthodrome") that is casted between two points on a
surface of a sphere, at a meridian (Gcal uses a geoid (rotation
ellipsoid) that is calculated taking pattern from the `World Geodetic
System', short W.G.S, that was designed in 1961).  Such an arc is the
shortest geodetic connecting line between two points on a sphere.
Indeed, the course angles on such an arc are changing continually,
because the circular line that is casted intersects each meridian with
another angle -- except the case, that both co-ordinates are referring
to exactly the same "meridian" (longitude), or to exactly the same
latitude.


File: gcal.info,  Node: Sun data,  Next: Moon data,  Prev: Geographical distance and course angle,  Up: Replacements with other argument

Sun data `%[FORMAT]?ARGUMENT' special texts
...........................................

  `%[FORMAT]o[*][MODE]ISO-6709:1983-CO-ORDINATE[,[+|-]MMMM|HH:[MM]]'
references the approximate time of *sunrise* by default,
`%[FORMAT]s[*][MODE]ISO-6709:1983-CO-ORDINATE[,[+|-]MMMM|HH:[MM]]'
references the approximate time of *sunset* by default,
`%[FORMAT]u[*][MODE]ISO-6709:1983-CO-ORDINATE[,[+|-]MMMM|HH:[MM]]'
references the approximate period of *visibility* of the Sun (solar day
length) by default,
`%[FORMAT]z[*][MODE]ISO-6709:1983-CO-ORDINATE[,[+|-]MMMM|HH:[MM]]'
references the approximate period of *non-visibility* of the Sun (solar
night length) by default.

  All these special texts can be used for at pleasure any geographic
point location, i.e. it is possible to determine different astronomical
values for any location on the globe, and that for at pleasure any
clocktime with a resolution of a single minute within the period of the
years AD 1 until AD 9999, that is respected by Gcal.

  The selection which value has to be calculated by these special texts
is done by specifying the MODE part of the preceding argument.
Actually, exactly 54 different modes can be used that are represented
by the `0'...`9', `a'...`z' and `A'...`R' characters, and which create
different kind of results that are depending on the special text used.
First of all, here is a table in which all usable modes are described
and explained sufficiently.  You can also see from this table, which
Sun oriented special text or texts are corresponding to which mode,
i.e. cause the determination of an astronomical value as it is
described in the table:

*Mode*  *Special      *Description*
        text*         

`0'     `o', `s'      Calculates the approximate midnight time of the Sun.
                      The astronomical midnight time of the Sun is at
                      that clocktime, when the Sun holds an "azimuth"
                      (horizontal angular distance between the vertical
                      circle, that passes the Sun, and the North point)
                      of either precisely 0 degrees of precisely 180
                      degrees ("noon line"), which depends on the season
                      and the geographical location.  At that clocktime,
                      the Sun is close its "lowest culmination point",
                      i.e. close the lowest point below or above the
                      horizontal plane the Sun transits during this day.

`1'     `o', `s'      Calculates the approximate noon time of the Sun.
                      The astronomical noon time of the Sun is at that
                      clocktime, when the Sun holds an azimuth of either
                      precisely 180 degrees of precisely 0 degrees (noon
                      line), which depends on the season and the
                      geographical location.  At that clocktime, the Sun
                      is close its "highest culmination point", i.e.
                      close the highest point above or below the
                      horizontal plane the Sun transits during this day.
                      People of Islamic faith normally pray for the
                      second time on the day during the period, which is
                      between the astronomical noon time of the Sun (or
                      some minutes later) and the Islamic prayer time by
                      the name of "Asr".  These people commonly use the
                      term "Zuhr" for this prayer time.  The timing of
                      Asr depends on the length of the shadow cast by a
                      vertical pole ("gnomon").  According to the Shafi
                      school of jurisprudence, Asr begins when the length
                      of the shadow of a vertical pole exceeds the length
                      of the pole.  According to the Hanafi school of
                      jurisprudence, Asr begins when the length of the
                      shadow exceeds twice the length of the vertical
                      pole.  In both cases, the minimum length of the
                      shadow at astronomical noon time of the Sun is
                      subtracted from the length of the shadow before
                      comparing it with the length of the pole.  *Note
                      Islamic Asr-1 prayer time: x-Sun-asr-1, and *Note
                      Islamic Asr-2 prayer time: x-Sun-asr-2, for further
                      details.

`2'     `o'           Calculates the approximate time when the center of
                      the Sun passes a reference altitude of 0 degrees on
                      a "mathematical-geocentric" horizon in the morning;
                      thus rising.  A mathematical horizon is a purely
                      geometrically-built horizon which disregards the
                      phenomenon of refraction as it arises in reality by
                      the influence of the Earth's atmosphere.  A
                      geocentrical horizon is the horizontal plane that
                      passes through the Earth's center, orthogonal to
                      the observer's local vertical.  In the further
                      context, the shorter term _mathematical horizon_ is
                      used which actually means the
                      mathematical-geocentric horizon.

`2'     `s'           Calculates the approximate time when the center of
                      the Sun passes a reference altitude of 0 degrees on
                      a mathematical horizon in the evening; thus setting.

`2'     `u'           Calculates the approximate period while the center
                      of the Sun is above a reference altitude of 0
                      degrees on a mathematical horizon; thus is visible.

`2'     `z'           Calculates the approximate period while the center
                      of the Sun is below a reference altitude of 0
                      degrees on a mathematical horizon; thus is
                      non-visible.

`3'     `o'           Calculates the approximate time when the upper limb
                      of the Sun passes a reference altitude of 0 degrees
                      on a mathematical horizon in the morning; thus
                      rising.  The above mentioned reference altitude is
                      computed from the value of the Sun's semidiameter
                      as it appear at that clocktime.  If the reference
                      altitude that is referring to the Sun's upper limb
                      is converted to a reference altitude that is
                      referring to the Sun's center, this results in a
                      value of about 16 arcminutes below the geocentric
                      horizon.

`3'     `s'           Calculates the approximate time when the upper limb
                      of the Sun passes a reference altitude of 0 degrees
                      on a mathematical horizon in the evening; thus
                      setting.  The above mentioned reference altitude is
                      computed from the value of the Sun's semidiameter
                      as it appear at that clocktime.

`3'     `u'           Calculates the approximate period while the upper
                      limb of the Sun is above a reference altitude of 0
                      degrees on a mathematical horizon; thus is visible.

`3'     `z'           Calculates the approximate period while the upper
                      limb of the Sun is below a reference altitude of 0
                      degrees on a mathematical horizon; thus is
                      non-visible.

`4'     `o'           Calculates the approximate time when the center of
                      the Sun passes a reference altitude of 34
                      arcminutes below the geocentric horizon in the
                      morning; thus rising.  The phenomenon of refraction
                      is already respected in this as it arises in
                      reality by the influence of the Earth's atmosphere,
                      and that with the standard value of 34 arcminutes,
                      which can indirectly be changed by using the
                      `--atmosphere' option.  *Note Fixed dates option
                      `--atmosphere=AIR-PRESSURE[,TEMPERATURE]':
                      x-atmosphere, how to change the base data of the
                      atmosphere, so that the atmospheric conditions as
                      defined by it are used to calculate the amount of
                      refraction.

`4'     `s'           Calculates the approximate time when the center of
                      the Sun passes a reference altitude of 34
                      arcminutes below the geocentric horizon in the
                      evening; thus setting.  The phenomenon of
                      refraction is already respected in this as it
                      arises in reality by the influence of the Earth's
                      atmosphere, and that with the standard value of 34
                      arcminutes, which can indirectly be changed by
                      using the `--atmosphere' option.

`4'     `u'           Calculates the approximate period while the center
                      of the Sun is above a reference altitude of 34
                      arcminutes below the geocentric horizon; thus is
                      visible.

`4'     `z'           Calculates the approximate period while the center
                      of the Sun is below a reference altitude of 34
                      arcminutes below the geocentric horizon; thus is
                      non-visible.

`5'     `o'           Calculates the approximate time when the upper limb
                      of the Sun passes a reference altitude of 34
                      arcminutes below the geocentric horizon in the
                      morning; thus rising.  This kind of rise time
                      calculation is done according to the standard
                      calculation method as it is commonly used
                      internationally.  The phenomenon of refraction is
                      already respected in this as it arises in reality
                      by the influence of the Earth's atmosphere, and
                      that with the standard value of 34 arcminutes,
                      which can indirectly be changed by using the
                      `--atmosphere' option.  *Note Fixed dates option
                      `--atmosphere=AIR-PRESSURE[,TEMPERATURE]':
                      x-atmosphere, how to change the base data of the
                      atmosphere, so that the atmospheric conditions as
                      defined by it are used to calculate the amount of
                      refraction.  The above mentioned reference altitude
                      is computed from the respective values of the Sun's
                      semidiameter and (standard) refraction as they
                      appear at that clocktime.  If the reference
                      altitude that is referring to the Sun's upper limb
                      is converted to a reference altitude that is
                      referring to the Sun's center, this results in a
                      value of about 50 arcminutes below the geocentric
                      horizon.

`5'     `s'           Calculates the approximate time when the upper limb
                      of the Sun passes a reference altitude of 34
                      arcminutes below the geocentric horizon in the
                      evening; thus setting.  This kind of set time
                      calculation is done according to the standard
                      calculation method as it is commonly used
                      internationally.  The phenomenon of refraction is
                      already respected in this as it arises in reality
                      by the influence of the Earth's atmosphere, and
                      that with the standard value of 34 arcminutes,
                      which can indirectly be changed by using the
                      `--atmosphere' option.  The above mentioned
                      reference altitude is computed from the respective
                      values of the Sun's semidiameter and (standard)
                      refraction as they appear at that clocktime.
                      People of Islamic faith normally pray for the
                      second-last time on the day at this clocktime, or
                      some minutes later.  These people commonly use the
                      term "Maghrib" for this prayer time.

`5'     `u'           Calculates the approximate period while the upper
                      limb of the Sun is above a reference altitude of 34
                      arcminutes below the geocentric horizon; thus is
                      visible.  This kind of visibility period
                      calculation is done according to the standard
                      calculation method as it is commonly used
                      internationally.

`5'     `z'           Calculates the approximate period while the upper
                      limb of the Sun is above a reference altitude of 34
                      arcminutes below the geocentric horizon; thus is
                      non-visible.  This kind of non-visibility period
                      calculation is done according to the standard
                      calculation method as it is commonly used
                      internationally.

`6'     `o'           Calculates the approximate time when the center of
                      the Sun passes a reference altitude of 6 degrees
                      below a mathematical horizon in the morning; thus
                      the beginning of "civil twilight".  The scattered
                      light of the Sun that is remaining at the beginning
                      of the civil twilight phase is in general not yet
                      sufficient for reading outside without artificial
                      illumination.

`6'     `s'           Calculates the approximate time when the center of
                      the Sun passes a reference altitude of 6 degrees
                      below a mathematical horizon in the evening; thus
                      the ending of civil twilight.

`6'     `u'           Calculates the approximate period while the center
                      of the Sun is above a reference altitude of 6
                      degrees below a mathematical horizon; thus the
                      period, while the center of the Sun is always above
                      -6 degrees.

`6'     `z'           Calculates the approximate period while the center
                      of the Sun is below a reference altitude of 6
                      degrees below a mathematical horizon; thus the
                      period, while the center of the Sun is always below
                      -6 degrees.

`7'     `o'           Calculates the approximate time when the center of
                      the Sun passes a reference altitude of 12 degrees
                      below a mathematical horizon in the morning; thus
                      the beginning of "nautical twilight".  The
                      scattered light of the Sun that is remaining at the
                      beginning of the nautical twilight phase is in
                      general not yet sufficient for navigation using a
                      sea horizon.

`7'     `s'           Calculates the approximate time when the center of
                      the Sun passes a reference altitude of 12 degrees
                      below a mathematical horizon in the evening; thus
                      the ending of nautical twilight.

`7'     `u'           Calculates the approximate period while the center
                      of the Sun is above a reference altitude of 12
                      degrees below a mathematical horizon; thus the
                      period, while the center of the Sun is always above
                      -12 degrees.

`7'     `z'           Calculates the approximate period while the center
                      of the Sun is below a reference altitude of 12
                      degrees below a mathematical horizon; thus the
                      period, while the center of the Sun is always below
                      -12 degrees.

`8'     `o'           Calculates the approximate time when the center of
                      the Sun passes a reference altitude of 15 degrees
                      below a mathematical horizon in the morning; thus
                      the beginning of "amateur-astronomical twilight".
                      The scattered light of the Sun that is remaining at
                      the beginning of the amateur-astronomical twilight
                      phase is in general yet so faint that most
                      astronomical observations can be made.

`8'     `s'           Calculates the approximate time when the center of
                      the Sun passes a reference altitude of 15 degrees
                      below a mathematical horizon in the evening; thus
                      the ending of amateur-astronomical twilight.

`8'     `u'           Calculates the approximate period while the center
                      of the Sun is above a reference altitude of 15
                      degrees below a mathematical horizon; thus the
                      period, while the center of the Sun is always above
                      -15 degrees.

`8'     `z'           Calculates the approximate period while the center
                      of the Sun is below a reference altitude of 15
                      degrees below a mathematical horizon; thus the
                      period, while the center of the Sun is always below
                      -15 degrees.

`8'     `o'           Calculates the approximate time when the center of
                      the Sun passes a reference altitude of 18 degrees
                      below a mathematical horizon in the morning; thus
                      the beginning of "astronomical twilight".  No
                      appreciable scattered sunlight is remaining at the
                      beginning of the astronomical twilight phase, the
                      sky is completely dark yet.  People of Islamic
                      faith normally pray for the first time on the day
                      during the period, which is between this clocktime
                      and the time of standard sunrise.  These people
                      commonly use the term "Fajr" for this prayer time.
                      *Note Standard rise time of the Sun:
                      x-Sun-standard-rise, for further details.

`9'     `s'           Calculates the approximate time when the center of
                      the Sun passes a reference altitude of 18 degrees
                      below a mathematical horizon in the evening; thus
                      the ending of astronomical twilight.  People of
                      Islamic faith normally pray for the last time on the
                      day at this clocktime, or some minutes later.
                      These people commonly use the term "Isha" for this
                      prayer time.

`9'     `u'           Calculates the approximate period while the center
                      of the Sun is above a reference altitude of 18
                      degrees below a mathematical horizon; thus the
                      period, while the center of the Sun is always above
                      -18 degrees.

`9'     `z'           Calculates the approximate period while the center
                      of the Sun is below a reference altitude of 18
                      degrees below a mathematical horizon; thus the
                      period, while the center of the Sun is always below
                      -18 degrees.

`a'     `o', `s'      Calculates the approximate "topocentric", apparent
                      "elevation" of the Sun, thus the vertical angular
                      distance between the Sun's center and the horizon,
                      in degrees and arcminutes as it happen at civil
                      midnight time.  Results with a negative sign
                      signify that the Sun's center is below the horizon
                      at the moment, and results with a positive sign
                      mean that the momentary center of the Sun is above
                      the horizon.  Observations of celestial objects
                      that are done from the surface of the Earth yield
                      in topocentrically based data.  The locations of
                      the celestial bodies are often at another place if
                      the data is topocentrically determined instead of
                      determine it "geocentrically", i.e. at the
                      fictitious center of the Earth.  This is mainly
                      caused by the refraction, which raises a celestial
                      body to another location as it is been in reality.
                      Because the terrestrial globe flattens towards the
                      pole caps and therefore cannot be taken as an
                      ideally shaped sphere, the individual Earth radius
                      between the observer's location and the center of
                      the Earth also affects the computation of
                      topocentrically based data.

`b'     `o', `s'      Calculates the approximate topocentric, apparent
                      azimuth of the Sun in degrees and arcminutes as it
                      happen at civil midnight time.

`c'     `o', `s'      Calculates the approximate topocentric, apparent
                      "declination" of the Sun, thus the vertical angular
                      distance between the Sun's center and the celestial
                      equator, in degrees and arcminutes as it happen at
                      civil midnight time.  Results with a negative sign
                      signify that the Sun's center is below the
                      celestial equator at the moment, and results with a
                      positive sign mean that the momentary center of the
                      Sun is below the celestial equator.

`d'     `o', `s'      Calculates the approximate topocentric, apparent
                      "ecliptic longitude" of the Sun, thus the
                      horizontal angular distance between the Sun's
                      center and the vernal equinox point on the
                      "ecliptic" (the zodiacal line or Sun's orbit), in
                      degrees and arcminutes as it happen at civil
                      midnight time.

`e'     `o', `s'      Calculates the approximate topocentric, apparent
                      "right ascension" of the Sun, thus the horizontal
                      angular distance between the Sun's center and the
                      hour circle that passes through the vernal equinox
                      point on the ecliptic, as time value in hours and
                      minutes as it happen at civil midnight time.

`f'     `o', `s'      Calculates the approximate topocentric, apparent
                      distance of the Sun from the Earth in "astronomical
                      units" as it happen at civil midnight time.  An
                      astronomical unit, abbreviated by ae, is equal to
                      the mean distance of the Sun from the Earth, which
                      is about 149,597,870.691 kilometers.

`g'     `o', `s'      Calculates the approximate topocentric, apparent
                      "horizontal parallax" of the Sun in degrees and
                      arcminutes as it happen at civil midnight time.
                      The horizontal parallax of the Sun specifies the
                      diameter of the Earth as it is seen from the
                      surface of the Sun.

`h'     `o', `s'      Calculates the approximate topocentric, apparent
                      semidiameter of the Sun in degrees and arcminutes
                      as it happen at civil midnight time.

`i'     `o', `s'      Calculates the approximate refraction of the
                      Earth's atmosphere in degrees and arcminutes as it
                      happen at civil midnight time.

`j'     `o', `s'      Calculates the approximate geocentric, apparent
                      elevation of the Sun in degrees and arcminutes as
                      it happen at civil midnight time.  Results with a
                      negative sign signify that the Sun's center is
                      below the horizon at the moment, and results with a
                      positive sign mean that the momentary center of the
                      Sun is above the horizon.

`k'     `o', `s'      Calculates the approximate geocentric, apparent
                      azimuth of the Sun in degrees and arcminutes as it
                      happen at civil midnight time.

`l'     `o', `s'      Calculates the approximate geocentric, apparent
                      declination of the Sun in degrees and arcminutes as
                      it happen at civil midnight time.  Results with a
                      negative sign signify that the Sun's center is
                      below the celestial equator at the moment, and
                      results with a positive sign mean that the
                      momentary center of the Sun is above the celestial
                      equator.

`m'     `o', `s'      Calculates the approximate geocentric, apparent
                      ecliptic longitude of the Sun in degrees and
                      arcminutes as it happen at civil midnight time.

`n'     `o', `s'      Calculates the approximate geocentric, apparent
                      right ascension of the Sun as time value in hours
                      and minutes as it happen at civil midnight time.

`o'     `o', `s'      Calculates the approximate geocentric, apparent
                      distance of the Sun from the Earth in astronomical
                      units as it happen at civil midnight time.

`p'     `o', `s'      Calculates the approximate geocentric, apparent
                      horizontal parallax of the Sun in degrees and
                      arcminutes as it happen at civil midnight time.

`q'     `o', `s'      Calculates the approximate geocentric, apparent
                      semidiameter of the Sun in degrees and arcminutes
                      as it happen at civil midnight time.

`r'     `o', `s'      Calculates the approximate "delta-t" in seconds as
                      it happen at civil midnight time.  Delta-t is the
                      difference between the Terrestrial Dynamical time
                      (abbreviated by TDT), that was formerly known as
                      _Ephemeris time_ (abbreviated by ET), and the
                      Universal time (UT).  Thus, `delta-t == TDT - UT'.

`s'     `o', `s'      Calculates the approximate, apparent location
                      oriented "sidereal time" (local sidereal time
                      (LAST), also known as _local star time_) in hours
                      and minutes as it happen at civil midnight time.  A
                      "star day" is the period between two consecutive
                      upper culminations of the vernal equinox point on
                      the ecliptic in the meridian of the observer's
                      location.  Therefore, the local "star time" is the
                      momentary period, which is past between the last
                      upper culmination of the vernal equinox point in
                      the meridian of the observer's location (the
                      momentary hour angle of the vernal equinox point),
                      thus the right ascension of the stars in the
                      observer's meridian at the moment.

`t'     `o', `s'      Outputs the base time as time value in hours and
                      minutes, for which the dynamical, i.e. depending on
                      the respective clocktime, astronomical data and
                      times of the Sun are calculated.  Without a given
                      `--time-offset=ARGUMENT' option, the astronomical
                      data and times of the Sun are always calculated for
                      0 o'clock Universal time (UTC/GMT).  *Note Calendar
                      option `--time-offset=ARGUMENT': x-time-offset, for
                      further details.

`u'     `o', `s'      Calculates the approximate Julian date in days as
                      it happen at civil midnight time.  *Note Julian day
                      number::, for further information about the Julian
                      date.

`v'     `o', `s'      Calculates the approximate "Julian Ephemeris date",
                      thus a Julian date that is corrected by _delta-t_,
                      in days as it happen at civil midnight time.

`w'     `o', `s'      Calculates the approximate difference between "true
                      solar time" and "mean solar time" as time value in
                      hours and minutes as it happen at civil midnight
                      time.  This so-called "equation of time" is a
                      correction to be added to the true solar time --as
                      read on a sundial-- to obtain the mean solar time.
                      A "true solar day" is the period between two
                      consecutive lower culminations of the Sun.  This
                      entity is taken as the base for deriving the true
                      solar time (as it is also shown by a sundial during
                      the day).  A star day is also known as a `mean
                      solar day'.  Because the Sun apparently shifts with
                      respect to the vernal equinox point on the ecliptic
                      due to the Earth's orbit around the Sun, the star
                      day and the true solar day have a different length.
                      As the true Sun namely moves irregularly through
                      the ecliptic, a fictitious "mean Sun" with a
                      symmetrical motion through the celestial equator is
                      used for deriving the mean solar time.  So, this
                      difference in time is a consequence of the
                      ellipticity and tilt of the Earth's orbit, causing
                      the irregular apparent movement of the Sun across
                      the sky.

`x'     `o', `s'      Calculates the difference of the approximate
                      topocentric, apparent elevation of Sun and Moon
                      (delta), at which the Sun is used as the reference
                      point, in degrees and arcminutes as it happen at
                      civil midnight time.  Results with a negative sign
                      signify that the momentary center of the Sun is at
                      an elevation that is below the momentary elevation
                      of the Moon's center; thus the Sun is lower than
                      the Moon.  Results with a positive sign signify
                      that the momentary center of the Sun is at an
                      elevation that is above the momentary elevation of
                      the Moon's center; thus the Sun is higher than the
                      Moon.

`y'     `o', `s'      Calculates the difference of the approximate
                      topocentric, apparent azimuth of Sun and Moon
                      (delta), at which the Sun is used as the reference
                      point, in degrees and arcminutes as it happen at
                      civil midnight time.  The result specifies the
                      horizontal angular distance, by which the momentary
                      center of the Sun is distant from the momentary
                      Moon's center, and that measured at the vertical
                      circles that pass the Sun and the North point and
                      the Moon and the North point.  Results with a
                      negative sign signify that the Moon is to the right
                      (clockwise) of the Sun if one looks to the Sun --
                      or alternatively expressed, that the Sun is to the
                      left (anti-clockwise) of the Moon.  Results with a
                      positive sign signify that the Moon is to the left
                      (anti-clockwise) of the Sun if one looks to the Sun
                      -- or alternatively expressed, that the Sun is to
                      the right (clockwise) of the Moon.

`z'     `o', `s'      Calculates the difference of the approximate
                      geocentric, apparent elevation of Sun and Moon
                      (delta), at which the Sun is used as the reference
                      point, in degrees and arcminutes as it happen at
                      civil midnight time.

`A'     `o', `s'      Calculates the difference of the approximate
                      geocentric, apparent azimuth of Sun and Moon
                      (delta), at which the Sun is used as the reference
                      point, in degrees and arcminutes as it happen at
                      civil midnight time.

`B'     `o'           Calculates the difference of the approximate
                      topocentric, apparent elevation of Sun and Moon
                      (delta), at which the Sun is used as the reference
                      point, in degrees and arcminutes as it happen at
                      standard rise time of the Sun.  *Note Standard rise
                      time of the Sun: x-Sun-standard-rise, for further
                      details.

`B'     `s'           Calculates the difference of the approximate
                      topocentric, apparent elevation of Sun and Moon
                      (delta), at which the Sun is used as the reference
                      point, in degrees and arcminutes as it happen at
                      standard set time of the Sun.  *Note Standard set
                      time of the Sun: x-Sun-standard-set, for further
                      details.

`C'     `o'           Calculates the difference of the approximate
                      topocentric, apparent azimuth of Sun and Moon
                      (delta), at which the Sun is used as the reference
                      point, in degrees and arcminutes as it happen at
                      standard rise time of the Sun.  *Note Standard rise
                      time of the Sun: x-Sun-standard-rise, for further
                      details.

`C'     `s'           Calculates the difference of the approximate
                      topocentric, apparent azimuth of Sun and Moon
                      (delta), at which the Sun is used as the reference
                      point, in degrees and arcminutes as it happen at
                      standard set time of the Sun.  *Note Standard set
                      time of the Sun: x-Sun-standard-set, for further
                      details.

`D'     `o'           Calculates the difference of the approximate
                      geocentric, apparent elevation of Sun and Moon
                      (delta), at which the Sun is used as the reference
                      point, in degrees and arcminutes as it happen at
                      standard rise time of the Sun.  *Note Standard rise
                      time of the Sun: x-Sun-standard-rise, for further
                      details.

`D'     `s'           Calculates the difference of the approximate
                      geocentric, apparent elevation of Sun and Moon
                      (delta), at which the Sun is used as the reference
                      point, in degrees and arcminutes as it happen at
                      standard set time of the Sun.  *Note Standard set
                      time of the Sun: x-Sun-standard-set, for further
                      details.

`E'     `o'           Calculates the difference of the approximate
                      geocentric, apparent azimuth of Sun and Moon
                      (delta), at which the Sun is used as the reference
                      point, in degrees and arcminutes as it happen at
                      standard rise time of the Sun.  *Note Standard rise
                      time of the Sun: x-Sun-standard-rise, for further
                      details.

`E'     `s'           Calculates the difference of the approximate
                      geocentric, apparent azimuth of Sun and Moon
                      (delta), at which the Sun is used as the reference
                      point, in degrees and arcminutes as it happen at
                      standard set time of the Sun.  *Note Standard set
                      time of the Sun: x-Sun-standard-set, for further
                      details.

`F'     `o', `s'      Calculates the difference of the approximate
                      astronomical midnight times of Sun and Moon (delta),
                      at which the Sun is used as the reference point, as
                      time value in hours and minutes as it happen at
                      astronomical midnight time of the Sun.  Results
                      with a negative sign signify that the astronomical
                      midnight time of the Sun is earlier than the
                      astronomical midnight time of the Moon; thus the
                      solar midnight is before the lunar midnight.
                      Results with a positive sign signify that the
                      astronomical midnight time of the Sun is later than
                      the astronomical midnight time of the Moon; thus
                      the solar midnight is after the lunar midnight.
                      *Note Astronomical midnight time of the Sun:
                      x-Sun-midnight, and *Note Astronomical midnight
                      time of the Moon: x-Moon-midnight, for further
                      details.

`G'     `o', `s'      Calculates the difference of the approximate
                      astronomical noon times of Sun and Moon (delta), at
                      which the Sun is used as the reference point, as
                      time value in hours and minutes as it happen at
                      astronomical noon time of the Sun.  Results with a
                      negative sign signify that the astronomical noon
                      time of the Sun is earlier than the astronomical
                      noon time of the Moon; thus the solar noon is
                      before the lunar noon.  Results with a positive
                      sign signify that the astronomical noon time of the
                      Sun is later than the astronomical noon time of the
                      Moon; thus the solar noon is after the lunar noon.
                      *Note Astronomical noon time of the Sun: x-Sun-noon,
                      and *Note Astronomical noon time of the Moon:
                      x-Moon-noon, for further details.

`H'     `o'           Calculates the difference of the approximate
                      standard rise times of Sun and Moon (delta), at
                      which the Sun is used as the reference point, as
                      time value in hours and minutes as it happen at
                      standard rise time of the Sun.  Results with a
                      negative sign signify that the standard rise time
                      of the Sun is earlier than the standard rise time
                      of the Moon; thus the sunrise is before the
                      moonrise.  Results with a positive sign signify
                      that the standard rise time of the Sun is later
                      than the standard rise time of the Moon; thus the
                      sunrise is after the moonrise.  *Note Standard rise
                      time of the Sun: x-Sun-standard-rise, and *Note
                      Standard rise time of the Moon:
                      x-Moon-standard-rise, for further details.

`H'     `s'           Calculates the difference of the approximate
                      standard set times of Sun and Moon (delta), at
                      which the Sun is used as the reference point, as
                      time value in hours and minutes as it happen at
                      standard set time of the Sun.  Results with a
                      negative sign signify that the standard set time of
                      the Sun is earlier than the standard set time of
                      the Moon; thus the sunset is before the moonset.
                      Results with a positive sign signify that the
                      standard set time of the Sun is later than the
                      standard set time of the Moon; thus the sunset is
                      after the moonset.  *Note Standard set time of the
                      Sun: x-Sun-standard-set, and *Note Standard set
                      time of the Moon: x-Moon-standard-set, for further
                      details.

`I'     `o', `s'      Calculates the approximate topocentric, apparent
                      elevation of the Sun in degrees and arcminutes as
                      it happen at astronomical midnight time of the Sun
                      (topocentric "midnight height").  *Note
                      Astronomical midnight time of the Sun:
                      x-Sun-midnight, for further details.

`J'     `o', `s'      Calculates the approximate topocentric, apparent
                      elevation of the Sun in degrees and arcminutes as
                      it happen at astronomical midnight time of the Sun
                      (topocentric "midnight height").  *Note
                      Astronomical noon time of the Sun: x-Sun-noon, for
                      further details.

`K'     `o'           Calculates the approximate topocentric, apparent
                      elevation of the Sun in degrees and arcminutes as
                      it happen at standard rise time of the Sun
                      (topocentric "rise height").  *Note Standard rise
                      time of the Sun: x-Sun-standard-rise, for further
                      details.

`K'     `s'           Calculates the approximate topocentric, apparent
                      elevation of the Sun in degrees and arcminutes as
                      it happen at standard set time of the Sun
                      (topocentric "set height").  *Note Standard set
                      time of the Sun: x-Sun-standard-set, for further
                      details.

`L'     `o'           Calculates the approximate topocentric, apparent
                      azimuth of the Sun in degrees and arcminutes as it
                      happen at standard rise time of the Sun
                      (topocentric "rise azimuth").  The horizontal
                      angular distance between the topocentric rise
                      azimuth and the East direction is also known as the
                      topocentric "morning width" of the Sun.  *Note
                      Standard rise time of the Sun: x-Sun-standard-rise,
                      for further details.

`L'     `s'           Calculates the approximate topocentric, apparent
                      azimuth of the Sun in degrees and arcminutes as it
                      happen at standard set time of the Sun (topocentric
                      "set azimuth").  The horizontal angular distance
                      between the topocentric set azimuth and the West
                      direction is also known as the topocentric "evening
                      width" of the Sun.  *Note Standard set time of the
                      Sun: x-Sun-standard-set, for further details.

`M'     `o', `s'      Calculates the approximate geocentric, apparent
                      elevation of the Sun in degrees and arcminutes as
                      it happen at astronomical midnight time of the Sun
                      (geocentric "midnight height").  *Note Astronomical
                      midnight time of the Sun: x-Sun-midnight, for
                      further details.

`N'     `o', `s'      Calculates the approximate geocentric, apparent
                      elevation of the Sun in degrees and arcminutes as
                      it happen at astronomical midnight time of the Sun
                      (geocentric "midnight height").  *Note Astronomical
                      noon time of the Sun: x-Sun-noon, for further
                      details.

`O'     `o'           Calculates the approximate geocentric, apparent
                      elevation of the Sun in degrees and arcminutes as
                      it happen at standard rise time of the Sun
                      (geocentric "rise height").  *Note Standard rise
                      time of the Sun: x-Sun-standard-rise, for further
                      details.

`O'     `s'           Calculates the approximate geocentric, apparent
                      elevation of the Sun in degrees and arcminutes as
                      it happen at standard set time of the Sun
                      (geocentric "set height").  *Note Standard set time
                      of the Sun: x-Sun-standard-set, for further details.

`P'     `o'           Calculates the approximate geocentric, apparent
                      azimuth of the Sun in degrees and arcminutes as it
                      happen at standard rise time of the Sun (geocentric
                      "rise azimuth").  The horizontal angular distance
                      between the geocentric rise azimuth and the East
                      direction is also known as the geocentric "morning
                      width" of the Sun.  *Note Standard rise time of the
                      Sun: x-Sun-standard-rise, for further details.

`P'     `s'           Calculates the approximate geocentric, apparent
                      azimuth of the Sun in degrees and arcminutes as it
                      happen at standard set time of the Sun (geocentric
                      "set azimuth").  The horizontal angular distance
                      between the geocentric set azimuth and the West
                      direction is also known as the geocentric "evening
                      width" of the Sun.  *Note Standard set time of the
                      Sun: x-Sun-standard-set, for further details.

`Q'     `o'           Calculates the approximate time when the length of
                      the shadow cast by a vertical pole in the forenoon
                      is *equal* the length of the pole.  Nevertheless,
                      the minimum length of the shadow is subtracted from
                      the length of the shadow before comparing it with
                      the length of the pole.  *Note Fixed dates option
                      `--adjust-value=ARGUMENT': x-adjust-value, how to
                      change the shadow length factor.

`Q'     `s'           Calculates the approximate time when the length of
                      the shadow cast by a vertical pole in the afternoon
                      is *equal* the length of the pole.  Nevertheless,
                      the minimum length of the shadow is subtracted from
                      the length of the shadow before comparing it with
                      the length of the pole.  People of Islamic faith,
                      and that the people holding the _Shafi_ school of
                      jurisprudence, normally pray for the third time on
                      the day at this clocktime, or some minutes later.
                      These people commonly use the term "Asr" for this
                      prayer time.  *Note Astronomical noon time of the
                      Sun: x-Sun-noon, for more information.  And note
                      *Note Fixed dates option `--adjust-value=ARGUMENT':
                      x-adjust-value, how to change the shadow length
                      factor.

`Q'     `u'           Calculates the approximate period while the center
                      of the Sun is above a reference altitude, at which
                      the length of the shadow cast by a vertical pole is
                      of single or shorter length than the pole itself.

`Q'     `z'           Calculates the approximate period while the center
                      of the Sun is below a reference altitude, at which
                      a vertical pole either casts no shadow anymore, or
                      casts a shadow that is longer than the single length
                      of the pole itself.

`R'     `o'           Calculates the approximate time when the length of
                      the shadow cast by a vertical pole at forenoon is
                      *twice* the length of the pole.  Nevertheless, the
                      minimum length of the shadow is subtracted from the
                      length of the shadow before comparing it with the
                      length of the pole.  *Note Fixed dates option
                      `--adjust-value=ARGUMENT': x-adjust-value, how to
                      change the shadow length factor.

`R'     `s'           Calculates the approximate time when the length of
                      the shadow cast by a vertical pole in the afternoon
                      is *twice* the length of the pole.  Nevertheless,
                      the minimum length of the shadow is subtracted from
                      the length of the shadow before comparing it with
                      the length of the pole.  People of Islamic faith,
                      and that the people holding the _Hanafi_ school of
                      jurisprudence, normally pray for the third time on
                      the day at this clocktime, or some minutes later.
                      These people commonly use the term "Asr" for this
                      prayer time.  *Note Astronomical noon time of the
                      Sun: x-Sun-noon, for more information.  And note
                      *Note Fixed dates option `--adjust-value=ARGUMENT':
                      x-adjust-value, how to change the shadow length
                      factor.

`R'     `u'           Calculates the approximate period while the center
                      of the Sun is above a reference altitude, at which
                      the length of the shadow cast by a vertical pole is
                      of double or shorter length than the pole itself.

`R'     `z'           Calculates the approximate period while the center
                      of the Sun is below a reference altitude, at which
                      a vertical pole either casts no shadow anymore, or
                      casts a shadow that is longer than twice the length
                      of the pole itself.

  If no MODE is given, Gcal automatically uses that mode, which is
enabled by the mode character `5'.  If a mode character is given that
is not according to one of the `0'...`9', `a'...`z' and `A'...`R'
characters, Gcal also automatically uses that mode, which is enabled by
the mode character `5'.

  Gcal represents the Sun oriented special texts depending on the
selected mode using the following types and styles:

  1. Unsigned decimal based rational number value
     Unsigned decimal based rational number values are represented using
     the `N.N...' format by default.  A `*' character that is directly
     given before some mode characters causes Gcal to represent the
     value for another quantity.  For the mode characters, which

       a. cause the calculation of Earth/Sun or Earth/Moon distances,
          the calculated distance is represented in kilometers.

       b. cause the calculation of phase angles of the Moon, the
          calculated phase angle is represented as a phase value in
          percents.

     If definite events happen, Gcal displays special event oriented
     texts instead of using the previously described representations.
     *Note Event texts of the Sun oriented special texts:
     x-Sun-event-texts, where you can find the event oriented texts
     that are created for clocktime values, which are schematically and
     analogously used for the type of representation as it is described
     here.

  2. Signed decimal based rational number value
     Signed decimal based rational number values are represented using
     the `+|-N.N...' format by default.  A `*' character that is
     directly given before a mode character causes Gcal not to
     represent such values using another style.

     If definite events happen, Gcal displays special event oriented
     texts instead of using the previously described representations.
     *Note Event texts of the Sun oriented special texts:
     x-Sun-event-texts, where you can find the event oriented texts
     that are created for clocktime values, which are schematically and
     analogously used for the type of representation as it is described
     here.

  3. Clocktime value
     Clocktime values are represented in hours and minutes, and that in
     the `HH:MM' _24-hour_ format by default.  A `*' character that is
     directly given before a mode character causes Gcal to represent
     the clocktime value using the _12-hour_ format, thus to provide it
     with a time suffix.  *Note Actual local time `%t[ARGUMENT]'
     special text: x-Actual-local-time, for more details about the
     above mentioned time value template.

     If definite events happen, Gcal displays special event oriented
     texts instead of using the previously described representations:

        * In case Gcal is unable to compute the approximate clocktime
          by reason of a misspecified ARGUMENT, a `??:??' text will be
          created instead of the clocktime text.

        * In case Gcal calculates an approximate clocktime that refers
          to a previous or next day, or Gcal is unable to calculate a
          clocktime because the event calculated does not occur during
          this day, a `**:**' text will be created instead of the
          clocktime text.

        * In case Gcal is unable to calculate an approximate clocktime
          because the reference point of the astronomical object, thus
          either the center or the upper limb of the Sun's or the
          Moon's disk, is always above the respective reference
          altitude, a `++:++' text will be created instead of the
          clocktime text.

        * In case Gcal is unable to calculate an approximate clocktime
          because the reference point of the astronomical object, thus
          either the center or the upper limb of the Sun's or the
          Moon's disk, is always below the respective reference
          altitude, a `--:--' text will be created instead of the
          clocktime text.

  4. Unsigned time value
     Unsigned time values, which mostly denote a period or interval of
     time, are represented in hours and minutes using the `HHhMM''
     format by default.  A `*' character that is directly given before
     a mode character causes Gcal to represent the time value using
     another style, and that in decimal hours, i.e. in the `HH.H...'
     format.

     If definite events happen, Gcal displays special event oriented
     texts instead of using the previously described representations.
     *Note Event texts of the Sun oriented special texts:
     x-Sun-event-texts, where you can find the event oriented texts
     that are created for clocktime values, which are schematically and
     analogously used for the type of representation as it is described
     here.

  5. Signed time value
     Signed time values, which mostly denote a period or interval of
     time, are represented in hours and minutes using the `+|-HHhMM''
     format by default.  A `*' character that is directly given before
     a mode character causes Gcal to represent the time value using
     another style, and that in decimal hours, i.e. in the `+|-HH.H...'
     format.

     If definite events happen, Gcal displays special event oriented
     texts instead of using the previously described representations.
     *Note Event texts of the Sun oriented special texts:
     x-Sun-event-texts, where you can find the event oriented texts
     that are created for clocktime values, which are schematically and
     analogously used for the type of representation as it is described
     here.

  6. Unsigned angular value
     Unsigned angular values are represented in degrees and arcminutes
     using the `DDDdMM'' format by default.  A `*' character that is
     directly given before a mode character causes Gcal to represent
     the angular value using another style, and that in decimal
     degrees, i.e. in the `DDD.D...' format.

     If definite events happen, Gcal displays special event oriented
     texts instead of using the previously described representations.
     *Note Event texts of the Sun oriented special texts:
     x-Sun-event-texts, where you can find the event oriented texts
     that are created for clocktime values, which are schematically and
     analogously used for the type of representation as it is described
     here.

  7. Signed angular value
     Signed angular values are represented in degrees and arcminutes
     using the `+|-DDDdMM'' format by default.  A `*' character that is
     directly given before a mode character causes Gcal to represent
     the angular value using another style, and that in decimal
     degrees, i.e. in the `+|-DDD.D...' format.

     If definite events happen, Gcal displays special event oriented
     texts instead of using the previously described representations.
     *Note Event texts of the Sun oriented special texts:
     x-Sun-event-texts, where you can find the event oriented texts
     that are created for clocktime values, which are schematically and
     analogously used for the type of representation as it is described
     here.

  After the optional style and mode characters, the latitude and
longitude of the geographic co-ordinates follows, for which the
calculations must be made.  They must be conform the ISO-6709:1983
standard representation of latitude and longitude for geographic point
locations, so that the co-ordinate has to be declared like this:

   * Latitude (`+' for North and on the equator, `-' for South of the
     equator.)

    `+|-DD[.DD]'
          Degrees (2 digits), and optionally decimal degrees

    `+|-DDMM[.MM]'
          Degrees (2 digits), arcminutes (2 digits), and optionally
          decimal minutes

    `+|-DDMMSS[.SS]'
          Degrees (2 digits), arcminutes (2 digits), arcseconds (2
          digits), and optionally decimal seconds

   * Longitude (`+' for East and on the prime meridian (Greenwich), `-'
     for West of Greenwich and up to the 180th meridian.)

    `+|-DDD[.DD]'
          Degrees (3 digits), and optionally decimal degrees

    `+|-DDDMM[.MM]'
          Degrees (3 digits), arcminutes (2 digits), and optionally
          decimal minutes

    `+|-DDDMMSS[.SS]'
          Degrees (3 digits), arcminutes (2 digits), arcseconds (2
          digits), and optionally decimal seconds

   * Optionally, the relative height in meters above the sea level (`+'
     for heights above and on the sea level, `-' for heights below the
     sea level.)

    `[+|-N[N[N[N]]]]'
          Height in meters (integer number) in range `-9999'...`+9999'
          (1...4 digits)

  All components of the co-ordinates must have leadings zeroes in case
they have less digits than the templates shown above.  Declared decimal
seconds are not respected by Gcal.  Heights which have a negative sign
remain unrespected if Gcal determinates Sun and Moon data and times,
respectively.  In such a case, Gcal always uses the height `+0'.
Latitude and longitude co-ordinates, and the height of the observer's
location are connected without any separating characters, like
`+40-075+61', `+401213.1-0750015.1' or `+40.20361-075.00417+0061'.  See
the pertinent literature for more details.

  A time value `[+|-]MMMM|HH:[MM]', which is separated by a `,'
character, may trail the co-ordinate.  Such a time value informs Gcal,
about how many minutes MMMM respectively hours HH and minutes MM the
geographic location is displaced from Universal time (UTC/GMT).  This
time displacement value defines the timezone, which is actually valid
for this location.  If summer- and wintertimes are respected for the
location, you should include that change in time into the timezone
value for the period in which the summertime is valid, by which the
clock is put on during the summertime period -- such a change is either
subtracted from the timezone value for locations West of the prime
meridian (Greenwich), or it is added for locations East of the prime
meridian, because Gcal is actually unable to perform such operations
automatically!  *Note Actual local time `%t[ARGUMENT]' special text:
x-Actual-local-time, for more details about the above mentioned time
value template.  If no time displacement value is specified for a given
co-ordinate, Gcal assumes a time displacement value of `0', which is
equal to the actual Universal time (UTC/GMT).

  The following table informs you about which type of representation is
caused by a mode.  The previously defined numbering scheme, as it has
been used for the introduction of the types of representations, is used
as key value in the column that holds the type of representation.  The
table also contains a column that shows whether a mode enables
dynamical values, i.e. values that are depending on the respective
clocktime (if you use the `--time-offset=ARGUMENT' option, you can
change the respective clocktime that is used for calculating such
values).  In a next table column, it is listed whether the given
co-ordinate of the location influences the determination of a value,
and the last column of the table gives you the information whether a
given timezone value affects the values determination:

*Mode*  *Representation Type*  *Dynamical*    *Co-ordinate*  *Timezone*

`0'     3                      No             Yes            Yes
`1'     3                      No             Yes            Yes
`2'     3 or 4                 No             Yes            Yes
`3'     3 or 4                 No             Yes            Yes
`4'     3 or 4                 No             Yes            Yes
`5'     3 or 4                 No             Yes            Yes
`6'     3 or 4                 No             Yes            Yes
`7'     3 or 4                 No             Yes            Yes
`8'     3 or 4                 No             Yes            Yes
`9'     3 or 4                 No             Yes            Yes
`a'     7                      Yes            Yes            Yes
`b'     6                      Yes            Yes            Yes
`c'     7                      Yes            Yes            Yes
`d'     6                      Yes            Yes            Yes
`e'     4                      Yes            Yes            Yes
`f'     1 or 1a                Yes            Yes            Yes
`g'     6                      Yes            Yes            Yes
`h'     6                      Yes            Yes            Yes
`i'     6                      Yes            No             No
`j'     7                      Yes            Yes            Yes
`k'     6                      Yes            Yes            Yes
`l'     7                      Yes            Yes            Yes
`m'     6                      Yes            Yes            Yes
`n'     4                      Yes            Yes            Yes
`o'     1 or 1a                Yes            Yes            Yes
`p'     6                      Yes            Yes            Yes
`q'     6                      Yes            Yes            Yes
`r'     2                      Yes            No             No
`s'     3                      Yes            Yes            Yes
`t'     3                      Yes            No             No
`u'     1                      Yes            No             No
`v'     1                      Yes            No             No
`w'     5                      Yes            No             Yes
`x'     7                      Yes            Yes            Yes
`y'     7                      Yes            Yes            Yes
`z'     7                      Yes            Yes            Yes
`A'     7                      Yes            Yes            Yes
`B'     7                      No             Yes            Yes
`C'     7                      No             Yes            Yes
`D'     7                      No             Yes            Yes
`E'     7                      No             Yes            Yes
`F'     5                      No             Yes            Yes
`G'     5                      No             Yes            Yes
`H'     5                      No             Yes            Yes
`I'     7                      No             Yes            Yes
`J'     7                      No             Yes            Yes
`K'     7                      No             Yes            Yes
`L'     6                      No             Yes            Yes
`M'     7                      No             Yes            Yes
`N'     7                      No             Yes            Yes
`O'     7                      No             Yes            Yes
`P'     6                      No             Yes            Yes
`Q'     3 or 4                 No             Yes            Yes
`R'     3 or 4                 No             Yes            Yes

And now some examples to these special texts:

     The text `Sunrise at %o+5158+00738,120  in MS, BRD' will be
     expanded to
     ==> `Sunrise at 05:16 in MS, BRD', in case the actual system date
     is the 1st June 1998.

     The text `Sunset at %s*5+5158+00738,120  in MS, BRD' will be
     expanded to
     ==> `Sunset at 09:39pm in MS, BRD', in case the actual system date
     is the 1st June 1998.

     The text `Sun visible %u5+5158+00738,120  in MS, BRD' will be
     expanded to
     ==> `Sun visible 16h24' in MS, BRD', in case the actual system
     date is the 1st June 1998.

     The text `Sun non-visible %z*+5158+00738,120  in MS, BRD' will be
     expanded to
     ==> `Sun non-visible 7.607 in MS, BRD', in case the actual system
     date is the 1st June 1998.

     The text `Sun azimuth 0 o'clock=%s*a+5158+00738,120  in MS, BRD'
     will be expanded to
     ==> `Sun azimuth 0 o'clock=339d16' in MS, BRD', in case the actual
     system date is the 1st June 1998.

     The text `Equation of time %ot+00+000=%o*w+00+000,120  BRD' will
     be expanded to
     ==> `Equation of time +16h00'=+00h02'13.201" BRD', in case you
     call Gcal with the `--time-offset=16:' and `--precise' options and
     the actual system date is the 1st June 1998.

     The text `Julian date at %ot+00+000 =%ou+00+000' will be expanded
     to
     ==> `Julian date at +10h15'=2450965.927', in case you call Gcal
     with the `--time-offset=10:15' option and the actual system date
     is the 1st June 1998.

  Here is a list that reports about the used reference systems in a
short manner, describes other aspects that are unmentioned now, and
informs about the lacks and limitations that are existing for the Sun
oriented special texts:

   * All astronomical calculations are based on methods that use
     --astronomically seen-- low-precision elements, which of course is
     shown in the precision of the results that are caused by them.
     Nevertheless in most cases, these results can be treated as more
     as sufficiently precise if one measures their practical use.

   * All azimuth and elevation values are always referring to the
     center of the respective astronomical object, except the case, it
     is stated otherwise.

   * The base point of azimuth values, right ascension values and other
     ecliptic co-ordinate values is always measured clockwise relative
     to the geographical, true North (not the magnetic North as shown
     by a compass), where angular values for the North direction are
     both denoted as 0 degree and 360 degree.

   * All topocentrically based azimuth and elevation values are always
     corrected by the amount of atmospheric refraction.  Such a kind of
     correction is always done if the center of the respective
     astronomical object is above 2 degrees below the horizon.

   * Generally, the rise and set times of the Sun cannot be precisely
     predicted, because depending on unpredictable atmospheric
     conditions, i.e. the local weather conditions as they appear
     during these times change the amount of atmospheric refraction at
     the horizon, so that the precalculated rise and set times may
     throughout be in error by a minute or more.

   * The accuracy of rise and set computations decreases again at high
     latitudes, i.e. within in the solar Arctic Circle.  There, small
     variations in atmospheric refraction can change the time of
     sunrise or sunset by many minutes, since the Sun intersects the
     horizon at a very shallow angle.  For the same reason, at high
     latitudes, the effects of observer height and local topography are
     magnified and can substantially change the times of the phenomena
     actually observed, or even whether the phenomena are observed to
     occur at all.

   * The short explanations that are given to the different twilight
     phases all assume the model of ideal atmospheric conditions by
     default.  It is obvious that these explanations all become
     meaningless if other conditions occur in reality, like a cloudy
     sky or a badly polluted atmosphere.

*Please also note the following references:*

   * *Note Fixed dates option `--precise': x-precise, how to obtain a
     more precise representation of the values which are cause by these
     special texts.

   * And note *Note Calendar option `--time-offset=ARGUMENT':
     x-time-offset, how to change the clocktime, for which the
     dynamical, i.e. depending on the respective clocktime, Sun
     oriented special texts are calculated.

   * Likewise, see *Note Fixed dates option `--cycle-end=ARGUMENT':
     x-cycle-end, how the dynamical, i.e. depending on the respective
     clocktime, Sun oriented special texts are calculated for a series
     of clocktimes for the current day.

   * And also note *Note Fixed dates option `--adjust-value=ARGUMENT':
     x-adjust-value, how to change the reference altitude that is used
     to calculate the rise and set times, as well as the shadow length
     factor.

   * Furthermore, see *Note Fixed dates option
     `--atmosphere=AIR-PRESSURE[,TEMPERATURE]': x-atmosphere, how to
     change the base data of the atmosphere that influences the
     calculation of the Sun oriented special texts.

   * And last, note *Note Fixed dates option `--limit': x-limit, how to
     limit the rise and set times of the Sun to the actual day.

  All Sun oriented special texts *must* always be trailed by a
_whitespace_ character which is removed in output!

