The main reason I wanted to change the time is because of the time it takes to get older.
In fact, in a real year, your character would only gain 3 years (4 month = 1 year in game).
If a 1 month = 1 year in game, in one real year your character would gain 12 years old.
It would help the younger (like 10~12 year old) to get old enough without having to wait lot of real year.