Time::timegm - a UTC version of mktime()
use Time::timegm qw( timegm );
my $epoch = timegm( 0, 0, 0, 14, 6-1, 2012-1900 );
print "2012-06-14 00:00:00 UTC happened at ",
scalar localtime($epoch), " localtime\n";
The POSIX standard provides three functions for converting between integer epoch values and 6-component "broken-down" time representations. localtime and gmtime convert an epoch into the 6 components of seconds, minutes, hours, day of month, month and year, in either local timezone or UTC. The mktime function converts a local broken-down time into an epoch value. However, POSIX does not provide a UTC version of this.
This module provides a function timegm which has this ability.
Unlike some other CPAN implementations of this behaviour, this version does not re-implement the time handling logic internally. It reuses the mktime and gmtime functions provided by the system to ensure its results are always consistent with the other functions.
Returns the epoch integer value representing the time given by the 6 broken-down components.
As with POSIX::mktime it is not required that these values be within their "valid" ranges. This function will normalise values out of range. For example, the 25th hour of a day is normalised to the 1st hour of the following day; or the 0th month is normalised to the 12th month of the preceeding year.
The Time::Local module also provides a function called timegm() with similar behaviour to this one. The differences are:
Time::timegm::timegm() handles denormalised values (that is, seconds or minutes outside of the range 0 to 59, hours outside 0 to 23, etc..) by adjusting the next largest unit (such that 61 seconds is 1 second of the next minute, etc). Time::Local::timegm() croaks on out-of-range input. Time::Local also provides a function timegm_nocheck() which does not croak but it is documented that the behavior is unspecified on out-of-range values.
Time::timegm::timegm() is implemented by a light XS wrapper around the timegm(3) or _mkgmtime(3) function provided by the platform's C library if such a function is provided, so its behaviour is consistent with the rest of the platform. Time::Local re-implements the logic in perl code. Time::timegm will fall back to a perl implementation only if the XS one cannot be used.
Paul Evans <email@example.com>
To install Time::timegm, copy and paste the appropriate command in to your terminal.
perl -MCPAN -e shell
For more information on module installation, please visit the detailed CPAN module installation guide.