Secretary and executive officer of the district school board.

The district school superintendent shall be the secretary and executive officer of the district school board, provided that when the district school superintendent is required to be absent on account of performing services in the volunteer forces of the United States or in the National Guard of the state or in the regular Army or Navy of the United States, when said district school superintendent shall be called into active training or service of the United States under an Act of Congress or pursuant to a proclamation by the President of the United States, the district school superintendent shall then be entitled to a leave of absence not to exceed the remaining portion of the term for which he or she was elected.