Putting the defender day on the 17th of July seems like a bit of an arbitrary date, especially since we've been a defender region long before that resolution was passed (which makes the whole concept of defender day questionable and I don't like it in the first place) but if you really wanted it I guess it would be better to have it a month earlier on the 13th of June when it was proposed.

As for moving it to the cultural act, i don't think it really makes sense. The cultural act is more for placing definitions and official things to tell people how to describe our region, and it's very much a "we would like you to call it this" while the holiday act is a much more important and much more tsp focused law about the events inside the tsp.