It's more like the Time they spend reforming varies based on how gravely injured they were. Though, there is also what Vivec says in Morrowind:
to be a god: "It is like being a juggler. Things are always moving, and you learn to know where they are without even thinking about it. Only there are many, many things moving. And sometimes, like any juggler, you drop something. I'm afraid it has become a lot more a matter of dropping things lately. There's too much to do, and not enough time, and I'm losing my touch. Perhaps I'm growing old.
It is a bit like being at once awake and asleep. Awake, I am here with you, thinking and talking. Asleep, I am very, very busy. Perhaps for other gods, the completely immortal ones, it is only like that being asleep. Out of time. Me, I exist at once inside of time and outside of it.
It's nice never being dead, too. When I die in the world of time, then I'm completely asleep. I'm very much aware that all I have to do is choose to wake. And I'm alive again. Many times I have very deliberately tried to wait patiently, a very long, long time before choosing to wake up. And no matter how long it feels like I wait, it always appears, when I wake up, that no time has passed at all. That is the god place. The place out of time, where everything is always happening, all at once."