It is said that if you keep the watch running, the "servicing" or "overhaul" interval would/ should be shorter because, obviously, the inside would be worn faster. If you work the watch once a month, naturally, the servicing interval would/ should be longer.
(Note: whether the watch needs servicing would be yet another "subjective" judgement by you - but it is recommended to have it serviced if the watch starts running very very slow or very very fast, and/ or the position difference become so big, etc.)
As long as you don't mind such deterioration of accuracy, you can keep using it.