We have an automatic exemption (if you wish) after a certain age. Maybe 75?
We are also pretty lenient if you have vacations planned. As I mentioned upthread, we have several dates over a two month period to show up for. Once you get your two month window, you tell them which days you will be out of town.
But as I also said, sometimes it can be very late that the case is settled beforehand. This is a royal PITA if you are a teacher, like H was. We are always very short staffed for subs, and he liked to get them set up as early as possible. But then if he set one up the night before, and then it was settled and cancelled in the morning - he’d be stuck taking the day off anyway.