The London Perl and Raku Workshop takes place on 26th Oct 2024. If your company depends on Perl, please consider sponsoring and/or attending.
 / 
Date-Set-Timezone-0.02
/ Date::Set::Timezone

NAME

Date::Set::Timezones - Date set math with timezones and DST

SYNOPSIS

    use Date::Set::Timezone;

    $a = Date::Set::Timezone->event( at => '20020311Z' );      # 20020311

    # TODO! (see timezone.t for some examples)

DESCRIPTION

Date::Set::Timezone is a module for date/time sets. It allows you to generate groups of dates, like "every wednesday", and then find all the dates matching that pattern. It also allows operations with timezones and daylight saving times.

This module is part of the Reefknot project http://reefknot.sf.net

It requires Date::ICal, Set::Infinite, and Date::Set.

It doesn't include timezones definitions.

TIMEZONE METHODS

tz

Translates a set to another timezone. It changes the timezone only. Time values are not changed.

    tz( { dst => $new_timezone_set , 
          name => ['STD-1', 'DST-1'], 
          offset => [ 3600, 2*3600 ] } )

This is a function. It doesn't change it's object. It returns a new object.

tz() without a parameter allows to work in 'local time' or 'UTC' mode (remove timezone info).

There might be conversion errors nearby DST endings because of 'repeated times' when time 'goes back'.

tz_change

Moves a set to another timezone. It changes both the timezone and time values, and adjusts DST.

    tz_change( { dst => $new_timezone_set , 
          name => ['STD-1', 'DST-1'], 
          offset => [ 3600, 2*3600 ] } )

This is a function. It doesn't change it's object. It returns a new object.

tz_change() without a parameter moves the set to 'UTC'.

DATE::SET METHODS

new

new() behaves differently from Date::Set::new() in that:

    $new_set = $set->new();

keeps timezone info.

as_string

as_string() behaves differently from Date::Set::as_string() in that it prints timezone/DST info.

If supplied with a timezone argument, as_string() stringifies the times under that timezone.

as_string(undef) stringifies the set as UTC times.

offset

offset() behaves differently from Date::Set::offset() in that times are adjusted for timezone/DST.

Parameter 'utc' specifies how the offset should be calculated:

    utc => 1  # uses UTC time
    utc => 0  # (default) uses clock time (local time); adjusts for timezone/DST

quantize

quantize() behaves differently from Date::Set::quantize() in that times are adjusted for timezone/DST.

Parameter 'utc' specifies how the offset should be calculated:

    utc => 1  # uses UTC time
    utc => 0  # (default) uses clock time (local time); adjusts for timezone/DST

AUTHOR

Flavio Soibelmann Glock <fglock@pucrs.br> with the Reefknot team, specially Martijn van Beers.