You're right again, I just realized a bit later so I've been playing with intersects:

sub hour_in_range {
    my ($dt_s, $dt_e, @hours) = @_;

    my $dt_span = DateTime::Span->from_datetimes(
        start => $dt_s, end => $dt_e
    );

    for my $hour (@hours) {
        my $dt = $dt_s->clone()
                      ->truncate( to => 'day' )
                      ->add( hours => $hour );

        $dt->add( days => 1 ) if $dt < $dt_s;

        my $hour_span = DateTime::Span->from_datetimes(
            start => $dt, end => $dt
        );

        return 1 if $dt_span->intersects($hour_span);
    }

    return 0;
}

[download]

It's not as simple and efficient as your approach, but it shows how to use span intersection.

OTOH, I misunderstood the OP and was thinking that @hours = (1,11) was an interval (1am to 11am), not a list of hours to match.

In reply to Re^5: Check if Date interval contains Hour X by alexm
in thread Check if Date interval contains Hour X by gulden

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