I need count backwards from a date, eg, 3/16/18. I have entered a dateline starting B2 (2/16/18) through AD2 (3/16/18)--AD2 is my target date. Am looking for something like TargetDate-1 (TD-1)..TD-2, TD-3, etc, all the way back to B2 (2/16/18) or TD-28. Would appreciate a formula that counts...