I was invited to a wedding on Aug 6th which is a Sunday at 3pm. I wanted to know what is appropriate to wear if I decide to wear a tux. (pardon my ignorance but I assume that's what "black tie invited" means. It's far enough away that I can start shopping for a tux but I don't know what is acceptable to wear to a wedding at this time of day during this time of year. Any advice is much appreciated.