Primary duties are those duties of a position that -
(i) Are paramount in influence or weight; that is, constitute the basic reasons for the existence of the position;
(ii) Occupy a substantial portion of the individual's working time over a typical work cycle; and
(iii) Are assigned on a regular and recurring basis.
(2) Duties that are of an emergency, incidental, or temporary nature cannot be considered primary even if they meet the substantial portion of time criterion. In general, if an employee spends an average of at least 50 percent of his or her time performing a duty or group of duties, they are his or her primary duties.