At around the same time you get the letter from anju to deliver to Kafei in the stockpot inn. I've tried and these two events cannot take place in the same three day period, yet the results of both are shown in the end sequence. This cannot occur if Link is simply resetting time, since he couldn't possibly do both quests within the same three day period.
It requires a convergence of two or more realities in which he did both quests.
Actually, I would just have assumed that when Majora's Wrath was defeated, Kafei transformed back to normal and married Anju as planned, with no help from Link.