(a) Regular employees who leave the service of the City to enter that of the United States Armed Forces, or the services of the U.S. Maritime Commission, or who are drafted by the United States Government for civilian services, will upon their return, within ninety (90) days from release from such services, be granted all seniority rights as if continuously employed by the City during such service.
(b) Sick leave accrued prior to the date of an employee's entrance into the military service shall be preserved until his return to City employment.
(c) Whenever vacancies occur in the classified service by reason of military leaves of absence, appointments may be made for the duration of the emergency or earlier return to City service. All such appointments shall be subject to the priority rights of the permanent employees granted military leaves.