Glow predictions?

Mariah

Is there any way to get my Glow predictions to be more accurate? They have been off by 5 or more days each month, then I downloaded Flo during my last period and it got my O day spot on the 1st time.

I realize they are just that, predictions, but before I realized just how bad it was, I was getting my hopes up so much each month thinking I was late. Shouldn't it update as I update my ovulation and period dates?