I'm now on 28 day seasons too - you'll notice a really subtle change from one season to next.
My holidays are:
spring:
- Easter
- Pancake Day (British thing; nothing to do with Bob)
- love day
- Walpurgisnacht (but of Paganism sneaking its way in; bonfires basically)
summer:
- Midsummer BBQ (inspired by tales of Aussie Christmases)
- SimNation day - kinda like independance day, but without the independance bit
autumn:
- Harvest festival day - like thanksgiving, which we Brits don't celebrate.
- Bonfire night (British thing, google it; it's interesting) - basically fireworks
- Halloween
winter:
- xmas eve
- xmas day (too many traditions to fit into one day)
- Diwali, 'cause I like it
- new year
