Well, I have either too much pasture or too few horses because when l move my horses from one pasture to another I immediately mow the one they left. I generally keep them on a pasture for about a week but sometimes I get behind on my mowing and have to move them after only 5 days. I've got 3 pastures to rotate so I've never had them graze one done yet.
Also, with the 2 horses I have, I can't leave them out 24/7 on the pastures. I have to bring them back to the sacrifice paddocks late afternoon and put them back out in the morning. One horse gets gas colic on lush, rich grass and the other horse has Cushing's and I don't want him to founder. Right now we are getting a lot of rain, most of what we have missed this spring thus far so they are only out till 3 PM. Even their sacrifice paddocks have enough grass that neither horse is eating much hay. I split one flake between the 2 and have plenty left over come morning.
Sometimes you have to burn a few bridges to keep the crazies from following you!