Best teacher I had in university offered "unlimited time on tests". Their tests were hard as hell but they were scheduled after the last class of the day and ran until like 10 at night. It worked out to like 5 hours of test time even if most people could complete the test in like ~1.5-2 hours.

The policy was essentially "you have until the teacher/TA needs to go home" and given everyone in university is always swamped with work they were generally willing to stick around and get their own work done until it got super late and even then, even if you were the last test taker they'd generally negotiate a final 10-20 minutes with heads up so you could do your best to wrap up even if you weren't done.

But generally the rule is ~2x test time. The extended test time accomodation is normally listed as "double time" in my experience even if profs were generally willing to give you more than 2x time if you were still making meaningful progress.

Given the context of this discussion, the answer would be "whatever extra time they're giving to the disabled folks".