We had our place divided into sixteen 5-acre paddocks and two 10 acre paddocks. Cows moved to a fresh paddock mostly every day, though at some times of peak grass growth, they *might* stay in one paddock for as much as 3 days. They were ALWAYS ready to move to a new paddock... took longer to walk/drive out there than it did to move them, unless there were new stupid baby calves that you'd have to try to get to follow mom & rest of the herd.
80 cows + 20-40 calves would hammer a 5 acre paddock in short order, some times of the year.
The longer they stay in one paddock the more grass that they pee and poop and lie on... and don't/won't eat. We shot for a 21-30 day period before they came back to a previously grazed paddock; longer was better, but sometimes we had to run them through faster.