My dad just started with Exelon today, is it better to change Exelon at 23 hours or at 25 hours? Dad will be at medical appointment at 24 hr.

Either should work, but personally I would do 25.

Rach, you should ask the pharmacist this question.

My personal experience, doesn't matter, as long as the drug is given daily at approximately the same time. Hospitals say within an hour when you are being given acute care meds.