(a) Public schools may not be in session on school holidays, which are Labor Day, Thanksgiving Day, the day immediately following Thanksgiving Day, Christmas Day, New Years Day, Memorial Day, and the Fourth of July. If one of these holidays falls on a Saturday, the Friday immediately preceding is a school holiday. If one of these holidays falls on a Sunday, the Monday immediately following is a school holiday. A teacher may not be required to perform employment services on these holidays, nor may the salary of a teacher be diminished because the teacher does not perform employment services on a school holiday.
(b) The public schools shall be in session on all other holidays falling upon school days and shall conduct appropriate exercises in recognition of the day.
(c) The governing body of the school district may declare additional holidays.