Frontier moved a few of my flights by about 2 hours. They sent me an email offering cancellation (which I can always do as a Gold member) and saying "no action is required". I have gotten 3 or 4 of these emails, plus a few texts, for EACH of the schedule changes. It's as if "no action is required" really means "we will bug you until you click through and say that you are just fine with having the trip that you only bought because the time was ideal changed to a trip that you would not have bought because the time was bad".