Perl convert date timezone without datetime module

Question

I have a date in the format: 05/26/2013 06:08:00
The timezone of above date is GMT -7

how can i change the above to GMT date and time and in format: 26 May 2013 13:08:00 GMT

Note: I cannot install any perl module. I know that i can do this easily via DateTime but i cannot install it.

Thanks.

Answer 1

You can use Time::Piece which should be included with your Perl installation.

use Time::Piece;

my $datetime = '05/26/2013 06:08:00';
$datetime   .= '-0700'; # attach the timezone offset

my $dt = Time::Piece->strptime($datetime, '%m/%d/%Y %H:%M:%S %z');
print $dt->strftime('%d %b %Y %H:%M:%S');

Answer 2

Assuming your local time is already set to GMT-7, simply:

use POSIX 'mktime', 'strftime';
my $datetime = '05/26/2013 06:08:00';
my ($month,$day,$year,$hour,$min,$sec) = $datetime =~ m{^([0-9]+)/([0-9]+)/([0-9]+) ([0-9]+):([0-9]+):([0-9]+)\z}
    or die "invalid datetime $datetime\n";
my $formatted_time = strftime '%e %B %Y %T %Z', gmtime mktime $sec,$min,$hour,$day,$month-1,$year-1900,0,0,0;

You may want %d instead of %e and/or %b instead of %B; see http://pubs.opengroup.org/onlinepubs/9699919799/functions/strftime.html and verify that the desired format specifiers are supported on your system.