this is just like asking how often should you do water changes.....there is no golden rule, blanket rule, or anything written in stone....there are too many different factors that come into play.....tank size, types of fish, how many fish, what your feeding, how often your feeding, type of filter, flow rate of filter, etc etc....
some filters i clean once a week, some every two weeks, some every three weeks....its really something you just need to get used to and go by feel....i would never recommend cleaning any filter more than once a week.....cleaning too often can be more harmful than not enough....