ok, well don't use the UTH until you have a thermostat, they can get up to 150+ degrees unregulated.
Don't bother with the thermostats sold in pet stores, they are dusk and not worth your money.
Here is a good one if you are on a budget.
http://www.amazon.com/Hydrofarm-MTPR.../dp/B000NZZG3S
You really don't need anything more than natural light as far as Day/Night cycling... nor should you drop temperatures at night. (but having one is fine)
BP's in the wild hide in rodent burrows and termite mounds during the day, and come out at night... so they rarely see daylight.