[] (ActiveSupport::TimeZone)

    # File lib/active_support/values/time_zone.rb, line 385
          def [](arg)
            case arg
              when String
                ZONES_MAP[arg]
              when Numeric, ActiveSupport::Duration
                arg *= 3600 if arg.abs <= 13
                all.find { |z| z.utc_offset == arg.to_i }
              else
                raise ArgumentError, "invalid argument to TimeZone[]: #{arg.inspect}"
            end
          end