Illinois Statutes Chapter 40. Pensions § 5/11-216. Basis of service credit

(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  1 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.