Confused about wedding times and appropriate dresses

This is a 2 parter:
1. I have a black tie optional wedding this Friday to go to. The ceremony is at 4. Should I wear a sort of long black dress or is that wrong? Is a shorter black dress better? Or should I wear color? I feel so weird being all dressed up in the middle of the afternoon.

2. My ceremony will be at 3 but my reception will be at 7. Is it okay for my bridesmaids to wear tea length dresses or is that too informal?

1. I think a simple elegant balck dress is acceptable for informal as well as formal weddings. So I don't think you could go wrong. Also, it will still be a Friday night wedding, even if it is starting at 4. Also it sounds semi-formal because it is black tie optional.

2. I am having a saturday night wedding and want my BM to have tea length as well - I too was concerned with the formality issues, but many girls have told me that it is popular to have tea length even on a Sat. night. So if that is what you want go for it!