NAME

Timezones::US - Provides US time zone data and subroutines for use with modules 'DateTime::US' and 'LocalTime'

SYNOPSIS

use Timezones::US;

DESCRIPTION

Raku module Timezones::US provides constant US time zone data (currently valid through the year 2030) to be used by related date and time dynamic modules.

The following table shows the time zones included:

Exported constants

The following constants are automatically exported into the using environment:

• SEC-PER-HOUR

  Seconds per hour: 3600

• @tz

  A list of time zones (lower-case symbols)

• %tzones

  A hash of all US time zone abbreviations keyed by their symbols (lower-case) with values of names and UTC offsets

• %dst-exceptions

  A hash of US time zone abbreviations keyed by their symbols (lower-case) with values of states or regions and details of Daylight Saving exceptions (CAUTION: this an incomplete list at the moment)

• %utc-offsets

  A hash of US time zone abbreviations keyed by their symbols (lower-case) with value of their UTC offset in hours

• %offsets-utc

  A hash of US time zone offsets keyed by their hours with value of their symbols (lower-case)

Exported subroutines

The following subroutines are automatically exported into the using environment:

• begin-dst($year --> DateTime) {...}

  Return the time when DST (Daylight Saving Time) begins.

• end-dst($year --> DateTime) {...}

  Return the time when DST ends.

• is-dst(DateTime :$localtime! --> Bool) {...}

  Return True if the local time is DST, otherwise return False.

• is-dst(:$year!, :$month, :$day, :$hour, :$minute, :$second --> Bool) {...}

  Return True if the local time is DST, otherwise return False.

• show-us-data(--> Str) {...}

  List the time zone and DST data being used.

Note some of these routines are now duplicated in module DateTime::US, but those are (1) perpetual and (2) return Date objects instead of DateTime objects which are preferred for use by the author's module Calendar. As well, this module was designed to be completely standalone.

If the user requires "perpetual" DST dates for all all years affected under current US federal law, please use the routines in DateTime::US.

AUTHOR

Tom Browder tbrowder@acm.org

COPYRIGHT AND LICENSE

© 2022-2024 Tom Browder

This library is free software; you may redistribute it or modify it under the Artistic License 2.0.