Every employee is expected to work an eight-hour day, and every employee below the rank of GS-12 (everyone below the rank of Head or Chief) is expected to take a 30-minute lunch break and two 15-minute breaks during his or her day/night. Professional staff (physicians, nurses, the pharmacist, etc.) work on a three-shift schedule: 7 AM to 3 PM; 3 PM to 11 PM; 11 PM to 7 AM. The hospital operates year-round..