use Time::Local;
$time = timelocal($sec,$min,$hour,$mday,$mon,$year);  
$time = timegm($sec,$min,$hour,$mday,$mon,$year);

my ( $mday, $mon, $year ) = split '/', "01/12/2008";
$mon -= 1;   # Time::Local uses months 0..11 like gmtime() and localtime().
my $epoch_time = timegm(1,0,0,$mday,$mon,$year); # 1 second past midnight