In the heat of summer, the rattlesnakes hunt mainly at night.
I heard of someone who tried night hiking in the heat of summer and gave it up because of all the snakes out in the night. I'd expect this to be true anywhere south of Pennsylvania once it gets warm enough.
As for the LED headlamp for night hiking, if yours tend to give off a bluish light, blue blazes will appear absolutely WHITE. Beware. I know this, because in Georgia, walking at night, I took the trail to the left which was blazed blue. I discovered my error after about 45 minutes of walking, "Hey, this doesn't look like the AT" I said to myself. NO kidding, they look absolutely bone-white.