Hi,
You can 'substitute' budget period by any other available FM objects, which will be derived automatically from the posting period, e.g. 'fund', 'funded program', etc. You can define 12 entities for this object, symbolizing a period, budget them and control its consumption. This way, you'll have monthly budgetary control. Please, search this forum, as this question was discussed several times.
Regards,
Eli