If you have a uv light and want to use it, it has to be at daytime, just like normal daylight, prob. 12 hours in summer and maybe about 8 in winter. Just bring it down with the seasons. But having said that, with coastals you can use just normal cheap fluro, for daylight.
Only with Diamond Pythons I would use the expensive uvb light. I know they are nocturnal too, but they can have a tendency of developing a problem (diamond python syndrome) in later years, and uvb might be partly helpful. Of course natural sunlight is the best.
Cheers Artie