I can explain it for you but I can’t understand it for you. The gears in a watch sync up pretty closely. They all relate to each other in the manner in which they turn. There’s no need for a “leap gear” in a watch. See?
Well, that’s a different argument than the classical “Cosmic Watchmaker” argument. Still, I think it’s flawed. You are assuming the “watchmaker” intended the gears to match up in the way that you would expect or prefer. I can see no solid logical basis for making that assumption.
There's a need for one in my inexpensive Timex. It indicated March 1'st all day on February 29th.