use strict;
use warnings;
use Time::Local;
my $month = 2;
my $day = 29;
my $year = 2003;
eval {timelocal(0,0,0,$day,$month-1,$year-1900)};

if ($@) {
  print "Datum ungültig.";
}
else {
  print "Datum gültig.";
}

Datum ungültig.