I'm honestly not sure what "closing date" refers to. IMO, it refers to a point in time when an agreement was reached, but not necessarily when it was executed. When buying a house, you close on a date and agree to terms, but you don't NECESSARILY pay 100% of it right then and there.
Quite frankly, with the way that this is all set up (8x of the average closes up to the closing date), you CAN'T complete it without a closing date that has come and passed... because you can't take 8x of a number that does not yet exist.