No need to get into a pi$$ing contest, but as far as i can tell frost has squat to do with the timing of the does going into heat. We've had frosts in mid September here in Birmingham. Rut is still mid January +/- a week or so - at least that has been the case for the past 40 or so years. I cannot vouch for frost times anywhere else with any certainty. But near Camden, Ar, area, for the past 20 or so years, the peak has been mid-November +/- a week. Every research article points to a day-light length kick off ... which has to be 1000's of years ingrained I would think.