Is it possible to tell if the date is a holiday? I looked through the api for calendar (we're on 1.3.1 btw) and I didn't see anything that looked like it would return that.
here's one I was working on some time ago (I'm not from the US so I'm not entirely sure I have the parameters of the holidays correct) easter calculation is close, but is incorrect (this is when I stopped), you might be able to add a tweak or two, to get it right.
There's a hole in the bucket, dear Liza, dear Liza, a hole in the bucket, dear liza, a tiny ad:
a bit of art, as a gift, the permaculture playing cards