I certainly don't have as much data as some of you older gentleman have. but,
I have found that most of the buck activity starts right around my brothers b-day...
Oct. 21st
Which tells me that the main breeding is about to start, as everyone can imagine.
Could they come into heat a week or two earlier or later, I would guess yes.
If feed, weather, age or other unknown causes may cause some variance.

Guys ~ deer are not machines or cloned!
Just like us humans, there are variations amongst their species. You could "generalize" a bigger percentage of what deer do.
However, the only predictable thing about a deer, is that their UNPREDICTABLE.