I prefer week or 2 for vacation or something planned. Never told him that but that’s the notice i usually get. It works for me because that way I can plan other things. I also like routine so last minute would throw me off. And I don’t like to get into heavy stuff knowing that he won’t be there next week.
I can understand emergency and I wouldn’t get upset if it happened. Luckily he only cancelled once just couple hours before and it was due to weather and I was kind of expecting that.
But since most of them expect us to give them 24 notice I think it Would be nice if it worked the other way too. I wouldn’t like to get there just to find out he’s not there.