#!/usr/bin/perl
use DateTime;

print ("Enter the date in dd-mm-yyyy format : ") ;
$date = <STDIN> ;
chomp ($date) ;

while ($date ne "") {
	my ($d,$m,$y) = split '-',$date;
	warn "/!\\ wrong year format? $y\n" if $y!~/^\d{4}$/ ;
        if ( eval {DateTime->new(year=> $y,month=> $m,  day=> $d)}	) {
            print("You have entered valid data \n") ;
        } else {
            print ("You have entered invalid data \n") ;
        }
        $date = <STDIN> ; chomp($date) ;
}