The wedding I posted about earlier is, I am told, "formal but not black tie." It is also in mid-October, in Boston (ok, Andover), in the evening, and the ceremony may be (depending on the weather) either inside or outside. I'm fairly certain the reception will be inside because, you know, Boston, October. I am also told the bridesmaids' dresses are short. So, anyway, is this dress appropriate? If not, would some fancy assesories fancy it up? If not to both, what does "formal" mean anyway?

P.S. I'm aware I may be overthinking this whole thing, but indulge me if you will.