use warnings;
use strict;

use DateTime;

my ($month, $day) = (5, 1);

my $now = DateTime->now;
my $year = $now->year;

my $known_date = DateTime->new(
    year    => $year,
    month   => $month,
    day     => $day,
);

if ($now < $known_date) {
    # do stuff
}