"Moon light" is not really moon light if there is no dimmer control to, at least, try to reproduce the moon phases. So it doesn't matter, if you don't have such system.
The artificial way to provide "sun light" can be changed also (timer) to imitate the seasons (summer/ winter...), but it won't come closer to nature's changes, without the help of a nice dimmable system.
Most of us maintain the organisms alive without much worries about the moon light. The day light cycle varies a little from reef to reef.
People normally have the "daily light" of the systems between 8 and 12 hours a day.
I would say anything in that range to be fine.
My systems run 10 hours with light on.
It's up to you.
Grandis.