Depends on your volume. If you don't have any activity during the night, then you can schedule it daily (in some of the projects I saw, there was some activity and then it could collide with FMAVCREINIT, as it blocks some tables during execution). However, if you do have some activity, then weekends might be enough.
Also, depends on the execution time... Try and find the optimum for this. Also, revise the note I provided and try and see if these situations are frequent in your project. There is no 'golden' rule for this, I'm afraid.