I have to enter user's time in my database and show it to them next time they login as last login time.

You could use JavaScript to populate a hidden field with their localtime when they login.

If you don't want to rely on JS or some other client-side application, you'll need to have the user select his timezone from a form like our Timezone Settings. Then, if you simply store the result of time on login, you can generate the user's last login time in the user's time zone using

my $dt = DateTime->from_epoch(
    epoch     => $epoch_time_stored_in_db,
    time_zone => $time_zone_stored_in_db,
);

print $dt->strftime("Last login at %Y-%m-%d %H:%M:%S\n");
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You should be storing UTC time (also known as GMT) so that all of your timeframes are common across all timezones for consistency. Then, when you need to show the users their time - you can convert from GMT to localtime.

You can get the gmtime in seconds by using the Time::Local module. Here is a snippet that you can use to show how to do the time conversions:

use strict;
use warnings;

use Time::Local;

my $time      = time();

my $timegm    = timegm(gmtime($time));
my $gmt       = gmtime($time);

my $timelocal = timelocal(localtime($time));
my $lmt       = localtime($time);

print "TIME: [$time]\n";

print "GMT: [$timegm]\n";
print "GMT AS TEXT: [$gmt]\n";

print "LOCALTIME: [$timelocal]\n";
print "LOCALTIME AS TEXT: [$lmt]\n";
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To get the localtime of GMT use the seconds value of the gmtime in localtime

my $timelocal = timelocal(gmtime($timegm));
my $lmt       = localtime($timegm);
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