Public funds shall not be expended for the purpose of paying compensation to any faculty member or employee of a state higher educational institution for any period of absence from his assigned duties with such state higher educational institution unless the period of absence:
A. is a holiday or vacation period established in the published calendar of the institution;
B. comes within the official sick leave or annual leave policies promulgated by the regents of the institution; or
C. is approved by a designated administrative authority according to procedures established for this purpose by the regents.