Non-teaching personnel in the Department of Education are entitled to 15 days of vacation leave and 15 days of sick leave annually. Various types of leave must be filed in advance, including vacation leave which must be filed 5 working days in advance. Sick leave for 5 or more successive days requires a medical certificate. Teachers can earn up to 15 days of service/leave credits per year for work during summer, Christmas, or the school year, which can offset absences due to illness. Other leave benefits for teachers include study leave, indefinite sick leave, and rehabilitation leave for injuries sustained while performing work duties.