So, if I understand this correctly, once they notified you in February you had to clear your calendar for the third week of the month for the next 12 months just in case you were called. And now you have been called (with a four day notice.) I wish you well as you fulfill your duty.
My husband just missed being called to county jury duty. He was summoned to begin today, but when he checked by recorded message on Friday night he learned that #'s 5-521 had to report and that #'s 522-6?? were excused. He was # 536.