Section 40 ILCS 5/11-216 - Basis of service credit(a) In computing the period of service of any employee for the minimum annuities, the following provisions shall govern: (1) all periods prior to the effective date shall be computed in accordance with the provisions governing the computation of such service, except for a re-entrant or future entrant who was not in service on the day before the effective date; provided that no period of lay-off or leave of absence in excess of one year shall be counted in such period of service.(2) Service subsequent to the day before the effective date, shall include: (A) the actual period the employee performs the duties of his position and makes required contributions or performs such duties and is given a city contribution for age and service annuity purposes or minimum annuity purposes; (B) leaves of absence from duty, or vacation, for which an employee receives all or part of his salary; (C) periods during which the employee is temporarily assigned to another position in the service and permitted to make contributions to the fund; (D) periods during which the employee has had contributions for annuity purposes made for him in accordance with law while on military leave of absence during World War II; (E) periods during which the employee receives a disability benefit under this Article, or a temporary total disability benefit under the Workers' Compensation Act if the disability results from a condition commonly termed heart attack or stroke or any other condition falling within the broad field of coronary involvement or heart disease; and (F) any period included under item (c)(3) of Section 11-215.(b) Service during 6 or more months in any year shall constitute a year of service, and service of less than 6 months and at least 1 month in any year shall constitute a half year of service. However, the right to have certain periods of time considered as service as stated in paragraph 2 of Section 11-164 shall not apply for minimum annuity purposes.(c) For all other annuity purposes of this Article, the following schedule shall govern the computation of a year of service of an employee whose salary or wages is on the basis stated, and any fractional part of a year of service shall be determined according to said schedule: Annual or Monthly Basis: Service during 4 months in any one calendar year;
Weekly Basis: Service during any 17 weeks of any 1 calendar year, and service during any week shall constitute a week of service;
Daily Basis: Service during 100 days in any 1 calendar year, and service during any day shall constitute a day of service;
Hourly Basis: Service during 700 hours in any 1 calendar year and service during any hour shall constitute an hour of service.