Nearly every mature buck that I was tracking this year daylighted on October 31 or November 1. Most were on a scrapes, but in one instance, I believe the doe actually came into heat based on the change in travel patterns (the doe was a regular afternoon visitor) and the amount of mature bucks that showed up at a water source in daylight nearby. There had to have been chasing for the multiple bucks to be at the water. The deer remember it, know it from hormonal changes, are biologically programmed to do that, maybe a combination of all of the above. Are there deeper reasons? Possibly. I don't know and not sure if it matters for me. I like to hunt mature bucks and these couple days it is somewhat predictable for them make a mistake. Either way there is a trigger associated with the rut for them to expose themselves in daylight with or without a doe on these couple of days.
The first hot doe I can actually confirm in person this year was on November 6th. I had a huge buck frantically searching in daylight on November 5th and hit 2 different cameras. I hunted on the 6th and had him and the doe bedded down the ridge from me about 150 yards. 4 additional 2/3 year old bucks circling like vultures.
P.S. I had trail camera pics this year of 2 different does being chased by multiple bucks in January. The last one being January 26th. I'd say that's somewhat unusual but we had a massive mast crop this year and might be connected to the availability of food and thus the health of the deer.
