You don’t really want to tire yourself out while going for a max attempt, so most everything you do before said max attempt should be warm-up and ramping sets to get you ready for the max attempt.
Suppose your squat max goal is 315lb or some such-
So regular warm-up, which really shouldn’t tire you out.
Ramp up to ~70-75% your max however you like. Again, should be getting you ready for the max attempt and nothing more.
Then aim to hit the max attempt in 2-3 sets at most from there. Why bother tiring yourself out if your entire goal is to max?
What day should you do it?
Don’t max or even come close to max on a frequent basis. It probably won’t get you anywhere besides getting closer to being injured/leaving your body open to some physical ailment somewhere down the road.
Rep maxes, on the other hand… Are I believe the closest a person can get to willingly torturing themselves for some benefit.
And I believe you should do these frequently.
Provided that you have solid faith in your form and ability to handle whatever weight you’re moving.