When you think of an MMA fight night, you generally think of three nights on the weekly calendar. Usually, a fight night will occur on Thursday or Friday in the case of the PFL, Friday in the case of Bellator, or Saturday in the case of Cage Warriors and/or the UFC.
Ordinarily, Sunday is a night off for the sport as the fighters recuperate and rest up to heal from an aggressive week in training camp and the fans get ready for a new week at work beginning the next morning.