(질문)perl 함수형 예시를 좀 바꾸어 보려다..실패

#!/usr/bin/perl
 
use strict;
use warnings;
 
use Time::Piece;
use Time::Seconds;
 
my $first_day = Time::Piece->strptime("2015-01-01", "%Y-%m-%d");
my $every_day = day_iterator($first_day);
 
sub day_iterator {
    my $day = shift;
    return sub{
        my $today = $day;
        $day += ONE_DAY;
        return $today;
    }
}
 
print $every_day->(),"\n";
print $every_day->(),"\n";
print $every_day->(strftime("%c"),"\n";