[bo-n-aro]

I think it is the amount a daylight in a given 24 hours. Usually the this is close to the 2nd full moon after the fall equinox.
Kind-a like lay-un hens. You can trick them to lay twice a day by blacking out the hen house during the day and have two nights within 24 hours.
Lots of folks thinks it takes a cold front to tricker it but i think the cooler it is the longer they can run, so you might see more activity after a cold front.
I still feel very strongly that the best time to hunt is when you can...