How to change timezone for datetime value in Perl?

Question

With this function:

perl -e 'use Time::Local; print timelocal("00","00","00","01","01","2000"),"\n";' 

It will return the epoch-making time - but only in GMT - if I want to get the result in GMT + 1 (which is the local time of the system (TZ)), what should I change?

Thanks in advance,

Anders

Answer 1

There is only one standard definition for epoch time based on UTC, and not different eras for different time zones.

If you want to find the offset between gmtime and localtime , use

 use Time::Local; @t = localtime(time); $gmt_offset_in_seconds = timegm(@t) - timelocal(@t); 

Answer 2

 use DateTime; my $dt = DateTime->now; $dt->set_time_zone( 'Europe/Madrid' ); 

Answer 3

While Time :: Local is a smart solution, you might be better off using a more modern, object-oriented DateTime module. Here is an example:

 use strict; use DateTime; my $dt = DateTime->now; print $dt->epoch, "\n"; 

For time zones, you can use the DateTime :: TimeZone module.

 use strict; use DateTime; use DateTime::TimeZone; my $dt = DateTime->now; my $tz = DateTime::TimeZone->new(name => "local"); $dt->add(seconds => $tz->offset_for_datetime($dt)); print $dt->epoch, "\n"; 

CPAN Links:

Datetime

Answer 4

You just need to set the time zone. Try:

  env TZ = UTC + 1 perl -e 'use Time :: Local;  print timelocal ("00", "00", "00", "01", "01", "2000"), "\ n"; '

Answer 5

Time::Local::timelocal is the inverse of localtime . The result will be in the local time of your host:

  $ perl -MTime :: Local -le \
     'print scalar localtime timelocal "00", "00", "00", "01", "01", "2000"'
 Tue Feb 1 00:00:00 2000 

Do you want gmtime match this localtime ?

  $ perl -MTime :: Local '-le \
     'print scalar gmtime timelocal "00", "00", "00", "01", "01", "2000"'
 Mon Jan 31 23:00:00 2000 

Do you want it to be the other way around, localtime , which matches this gmtime ?

  $ perl -MTime :: Local -le \
     'print scalar localtime timegm "00", "00", "00", "01", "01", "2000"'
 Tue Feb 1 01:00:00 2000 

Answer 6

Another example based on DateTime :: Format :: Strptime

 use strict; use warnings; use v5.10; use DateTime::Format::Strptime; my $s = "2016-12-22T06:16:29.798Z"; my $p = DateTime::Format::Strptime->new( pattern => "%Y-%m-%dT%T.%NZ", time_zone => "UTC" ); my $dt = $p->parse_datetime($s); $dt->set_time_zone("Europe/Berlin"); say join ' ', $dt->ymd, $dt->hms; # shows 2016-12-22 07:16:29