Or, you could try this method which was pretty close to what worked for me, even though i had the excuse that i wasn’t given a contract for the next year until April:
Research a suitable substitute, quietly. Have lesson plans all planned out and left in your office or file.
Let everyone know that you’re off to hike the PCT, what an amazing journey it will be, and that you think you can be done by the time school starts.
Keep an online journal. Write a few times about how important this trail is to you, and how you’re worried you’re not going to get done in time.
In early August, (IF you’re still hiking, which face it many have quit by then) call your boss and tell him/her that you’re a month (or more?) from being done, that it would kill you after having walked 2000 miles already to have to stop short. Let him/her know that you know of a great substitute.
I know this is a risk that has to be assessed. Will you get fired? But the likelihood is that the impressive nature of what you’re doing, already 3/4 done, will influence your boss more then than it would by asking him in advance.
ATeacher