use DateTime;
use DateTime::TimeZone;

my $dt = DateTime->now; # same as ( epoch => time() )
print( $dt->hms, "\n" );

$dt->set_time_zone( 'America/New_York' );
print( $dt->hms, "\n" );

$dt->set_time_zone( 'EST' );
print( $dt->hms, "\n" );

##</code><code>##

21:10:32
17:10:32
16:10:32