Occassional.

Decided I'd have more luck doing this in advance, since Sunday will probably be fairly hectic.

I find different peoples view of occassions interesting. Some won't turn up to one without sprucing up a bit, some always wear a suit, some just won't go, and some don't really care. In some cases, people see them as quite serious affairs, whereas others think they should be taken a bit more light-heartedly. (For instance, at the weddings I've been to so far, there was a significant difference in the bridal marches; one was composed by the groom [who plays a fair few instruments and is in a big band] and the other used I'm Yours. Slight difference.)

Personally, I think there's a reason they're called occasions. There's a dual meaning to the word, and one is inherent in the other. Occassions are good on occassion. Too often, and the good parts of them can be lost. That's my view, at least.