use strict;
use warnings;

use Time::Piece;
use Test::More tests => 366 * 2 + 1;

my $dstr = '01/01/2023';

for (1 .. 366) {
    my $t = Time::Piece->strptime ($dstr, '%d/%m/%Y');
    my $nt = $t - 86400;
    isnt $dstr, $nt->dmy ('/');
    my $ddiff = $t->mday - $nt->mday;
    ok ($ddiff < 0 || $ddiff == 1), '1 day different or month wrap';
    $dstr = $nt->dmy ('/');
}
is $dstr, '31/12/2021';