All permanent, full-time employees in the City service, who have satisfactorily completed six months service, shall be entitled to one personal leave day per calendar year which shall not be accumulated. This leave shall be used at the discretion of the employee whenever it does not interfere with the efficient operation of the City, as determined by the department head, or by the Mayor, whose decision shall be final.
(1970 Code Sec. 21.1-7)