#! /usr/bin/perl
use warnings;
use strict;

use Time::Piece;
use Time::Seconds qw{ ONE_DAY };

sub is_magical {
    my $s = shift;
    my %chars;
    undef @chars{ split //, $s };
    my ($first, $last) = (sort keys %chars)[0, -1];
    return (keys %chars == length $s
            and $last - $first + 1 == length $s)
}

my $t = 'Time::Piece'->strptime('2015-01-01', '%Y-%m-%d');
while () {
    print $t->ymd, "\n" if is_magical(join q(), $t->mon, $t->mday, $t->year);
    $t = $t + ONE_DAY;
}