AbigailII: I think what you really need is a speed rating of each player.

Something that before excepting a game with someone will tell you weather or not they will likely on average play daily or wait until the last possible second.

This value should be:
*boldly shown on the screen where you accept games.
*calculated independently for each game(I play ludo games quicker then say chess games) as well as an overal show in the format [this game/all games] ? should be used if no games of that type have been played for a while.

Suggested formula to calculate:
1) 10*average time taken/average time allowed shown to 1 decimal.
2) average number of days/move shown to 1 decimal.

in each of these systems lower number means faster players. for method 1 players could get values greater then 10 if they often take advantage of weekends and vacations as formula should just compute based on time restraints shown.

I.E. 5 day with vacation and weekend would give you
*14.0 if you waited to the last second without using vacation time
*16.0 if you used up 1 vacation day for each move you made also
*1.9 if on average you played 1 move a day but took a week off every 4th week