Don't take me wrong. You are completely correct. It is a guess. I like to think it is an educated guess, those results in evidence on the Sep 29, Oct 4, Nov 1, Nov 29, and Dec 31 ex-dividend dates.
Someday I wish I COULD just stay invested and collect dividends. I fact, I would LOVE it! I'm still trying to build my base to the point where maybe I could do that.