The courts should have a list of companies and how many days they pay for jury duty. My company had a 10 day limit and the court system knew it. Then it got changed to unlimited and the courts took advantage of it so it got changed back to 10 days. Usually at the start of any trial process (before jury selection) they tell you that the trial will last X number of days and would that be a hardship on anyone. Those that raise their hands are usually dismissed. Most counties have a call in system where you call in every evening and after a week if they don't need you, you are off the hook. I tried to get off once when I was a student and they just said, "Fine, come in during quarter break!" Harsh.

Good luck.
Karl