I think my best day is Wednesday. By then I've warmed up and am considering smart over comfort. Thursday I wear very smart casual (as opposed to business casual) because I'm ready for casual Friday but it's not here yet.
What's funny is that in my new job there is no such thing as casual Friday (every day is casual Friday), but I still observe it, and it is the only day I wear jeans. I just can't hack being in a manager position and not dressing like it at least somewhat. While trying to honor that I'm in LA and we are more laid back, lol!