Schedule of the School Day. The schedule of the school day, including the beginning and end of the school day and other important periods, shall be in writing. A school shall distribute annually its written schedule for the school day to the representatives of agencies placing students in the school and to the parents of students enrolled, as applicable. A school providing a general education program shall provide instruction at least 4 hours a day, Monday through Friday, exclusive of holidays, vacation days, and any other pertinent events or activities. In a school providing a special education program, the total hours in a school week shall be sufficient to implement each student's IEP. In a nursery school providing an educational program, other than a special education program, the length of the school day may not exceed 6 hours. Calendar of the School Year. A school shall develop a written calendar for each year that includes the name, address, and telephone number of the school, month, day, and year for the opening and closing of school, the specific and total number of days of instruction, the total number of hours a school is open for student attendance, holidays, vacations, and other pertinent events or activities in the schedule for the year. A school shall distribute its written calendar annually to the representatives of agencies placing students in the school and to the parents of students enrolled, as applicable. The calendar for the school year shall provide for a school year with at least 180 days of instruction. A school providing an elementary school or secondary school educational program, or both, shall be open for student attendance for a minimum of: 1,080 hours in a school year for elementary schools and nongraded educational programs; and 1,170 hours in a school year for secondary schools. The Department may grant a waiver of the length of the school year for natural disasters, civil disasters, or severe weather conditions.