First get all the letters you can, including one that states that for religious reasons you are never on the road after noon on Fridays. Have you Rov sign this and get it notarized. Call the number listed and try to speak to someone about this. If you are in school full time you cannot be compelled to miss school. You might get a postponement, though, rather than a dismissal. get a letter from the school as well.
I was called to jury duty one winter in a locale about 40 minutes from my house in good traffic, but typically more like an hour or hour and a quarter. I would not take such a chance on Fridays, as dismissal was at 3PM. I produced both that religious letter and a letter from my doctor truthfully stating a physical condition that I have that would make sitting for long periods of time in one place very problematic for me. I was excused.