For a couple of months during the summer, they are in their stalls all day and out at night because of the horse flies. The rest of the year, they have free access to the pasture during the day. We've had to start locking them up at night because one of the horses is allergic to grass. He jumps the electric fence during the night to get to the grass and has coliced.
One horse is new but the other 2 roam around 3 stalls that are 16x16. Once the new horse is acclimated, he'll be turned loose, too.