MY guys are out from dawn till dusk. From June until late September they are out 24/7 but they have good shelters, lots of trees and great pasture.
I want my guy in when it is dark and cold, in a warm dry stall, well groomed, feet picked clean and good hay, water and grain.
I will not board where a horse is out nights in the winter. While wild horse are out they know where the sheltered spots are. They don't stand out in the wind or rain like some force their horses to