I'm not sure there is a better time then another the way the seasons are set right now. When it finally gets back to ending on the 21st, I would think we could actually get more rutting action. For most of the hunters who don't get very far off the roads, the later the better. For those who get back into the country with fewer or no other hunting pressure is going on, I think the more responsive the elk will be and it won't really matter as much what part of the month it is, you will just have to change your tactics a bit to accommodate what faze of rut the elk are in.
My father and I can't get to far back to we really have to rely on calling to find elk. We usually get one or two opportunities but it makes it real difficult to be successful. I shot my bull on the second day of the season last year while in a cold calling set up.