I believe the most we've had for set hours was for one trainer. After scheduling several lessons in a row from 8am-1pm, it became a hassle for us who were cleaning to try to work around them and we felt we were in her way with our loud tractor and us having normal conversations between stalls. She was just told not to schedule anything until 11am, which gave us more than enough time to have everyone outside, fed, and that entire part of the barn spic and span.
In the summer when it's too hot or humid to go riding outside comfortably for most of the day, I've gone out riding with my BO starting at 8-9pm and not get back until 11pm or so. Last summer, there was a day I was determined to ride, but it was so disgustingly hot that I waited until literally midnight and didn't leave until after 1am (though I did shoot my BO a text saying I was the one outside, not some stranger as they live on the property).
Last edited by Poseidon; 05-01-2013 at 12:23 PM.