Day/night cycles matching the seasons would be important, you are trying to mimic the natural habitat. without correct photoperiod [hrs of light] snake will not know if its winter/autumn etc . temp and photoperiod as well as "cooling" are basic requirements of successful breeding.........so Im told!
I make no special effort to provide day/night for my pythons, i just leave the blinds open, that gives enough light for them to notice a change.
Temps are alot more important for breeding than light cycles.
I've never made any special effort with light cycles either. Even when breeding temperature is the main thing. Snakes do not require uv. Well I shouldn't say all snakes because there's always an exception to the rule, but for the most part anyway.