Our pastors get a sabbatical every few years (I think maybe every 5, but don't hold me to that.)

It's usually a mixture of time to relax and time to grow. For instance, they may observe different churches to see how things are done differently, or they may take a short class that they otherwise couldn't take. Or they might go to some conferences. Or do some self-study. (Or a mixture of some of the above.)

They always come back refreshed, renewed, and ready to apply what they learned while on sabbatical.

So, while it's partly about time off, it's much more about time to grow and learn in ways that they can't when they're involved in the day-to-day work.