They don't make it easy to get excused from any Jury that I know of. Among other candidates called when I was, were a few who said they had good excuses. They weren't even allowed to present them during the Jury Selection process until their name came up.

Most of those who were excused were dismissed because either the defense attornies, Prosecutor or both felt the candidate had a bias or was predjudiced in some way.

When I was called, I had a day job that was part salary, part commission. The company I worked for continued to pay my salary, but of course, I could make no commissions while in court.
Eddie