how long do people usually wait to hear from a publisher that has a reading period?

i submitted a nonfiction manuscript back in april to a university press. their reading period was june 1 to september 1. this is my first time submitting anything to any publisher ever, so i’m expecting a rejection, but i have no idea when to expect that rejection. is it normal to hear nothing until after a reading period is over? and if so, how long will i probably wait not that the reading period is over? obviously, i know there are no guarantees and every publisher is different, but if i could get an idea of a ballpark timeframe to ease my email-checking-induced-anxiety, it’d be a lifesaver! thanks!