.W.. What? Certify system? I'm not sure what you mean by *that*, but if you meant aging in the sense that a person gets "older" as they stay in the game, I may have a solution for that.

Basically, you have a variable to hold the time that the it was when the player first joined the game (age 0, if you will.). Then, every time you want to check age, simply subtract that from the current time and then do whatever mess you want to decide how much you want that to actually be (10 seconds = to day, for instance).

There's probably some other way that's a lot better, but that's how I'd do it.