my $offset = 30;

display(reverse((localtime(time() - 60 * $offset))[0 .. 5]));


sub display {
        my @t = @_;
        printf("%02d%02d%02d%02d%02d%02d\n", ($t[0] + 1900) % 100, $t[1] + 1, @t[2 .. 5]);
}