They need heat 24/7, you can’t just turn it off at night unless it’s around 85 in the entire room!
I use heat cable on a herpstat with steel probes very close to the heating source under the tubs.
Hot spot around 93 daytime, then the herpstat is programmed to 90 hot spot at night time. Some snakes hangout on the hot spot and some of my snakes spend more time on the cooler side of the tub.
Kaos Balls