I've never been on a jury or been called for jury duty. but at least where i live when you get called for jury duty all you have to do is call a number the night befor and they let you know if you have to show up the next morning.

I was called as a witness to testify once. that was an experience. damn jury didn't convict the guy even though i thought all the evidence pointed to him. howvever all they had was circumstantial evidence.