Anyone else like this idea, or think it'd work?

Instead of a fixed time limit for each move, I'd like an average time limit per move. That way I could play a lot one day, and then skip a few days and not worry about it. The average could be figured by the time after my opponent enters his move until I enter mine. That'd be my average. His would be based on the time after I enter my move until he moves. Seems like it'd work. A 15 move per month game would be the same as a move per day. There could be a buffer time at the start of the game so a timeout wouldn't happen in the first couple of moves, and then it'd be enforced. It might take a wide spread of averages to get the feel of which times I'd like to play, but after awhile I'd know. Both systems could still be offered, and it might even be possible to combine them for a hybred of the two.