Depends on when, generally speaking. Halloween and holiday weekends can be exceptions. E.g., Labor Day (if the parties start that early like they did this year), Columbus Day.... there's not typically a Sunday party on those weekends. I think there might have been a party ON Columbus Day Monday this year.
The Thursday parties don't typically start until October/late Sept. FWIW, I had mapped this out for another recent poster and these is what September looked like this past year (I only went to 9/23 for this).
9/2 - Friday
<Note: 9/5 was Labor Day - Monday>
9/8 - Thursday (note, in 2016 the Night of Joy event was 9/9-9/10, Friday-Saturday)
9/11 - Sunday
9/13 - Tuesday
9/16 - Friday
9/18 - Sunday
9/20 - Tuesday
9/23 - Friday
Hope that helps!