The council may adopt or provide for rules and regulations or ordinances concerning but not limited to annual leave, sick leave, special leave with full pay or with partial pay supplementing workers' compensation payments for employees injured in accidents arising out of and in the course of employment, hours of employment, holidays, working conditions, service award and incentive award programs, other personnel policies, and any other measures that promote the hiring and retention of capable, diligent, and honest career employees. (1917, c. 136, subch. 5, s. 1; 1919, cc. 136, 237; C.S., s. 2787; 1965, c. 931; 1971, c. 698, s. 1; 1979, c. 714, s. 2.)