I have various prescribed medications. They are always prescribed in multiples of 8 or 12 weeks, not 2 or 3 months. I'm not being argumentative, just the way it is for me. It may well be easier to have a diary note of "1st of the month, get my meds" but then some months have 30 or 31 days, Feb, 28 for example. As I'm on long terms meds that's the timescales my prescriptions are. For shorter term medication I would have a prescription for the amount of days the meds should have done their work and be discontinued.