Members of the police department shall be allowed service credit for sick leave granted pursuant to the City's policies and procedures manual of personnel regulations or the collective bargaining agreement. No member shall be entitled to disability pay and sick leave pay simultaneously. When authorized by the chief in accordance with the personnel policies and procedures manual or the collective bargaining agreement, a police officer may be granted a leave of absence. Service credit shall be allowed for a leave of absence for military duty only. (Code 1979, § 15-102)