(1) As of July 1, 1965, the basic unit of service time for volunteer firefighters is one fiscal year. Volunteer firefighters not continuously on the active membership list of a single qualifying volunteer fire company for the entire fiscal year shall not be listed on the annual certificate and shall not receive credit for service under the Volunteer Firefighters' Compensation Act for that fiscal year.

(2) A volunteer firefighter shall receive one year of credit for service under the Volunteer Firefighters' Compensation Act for each two full fiscal years of service performed prior to July 1, 1965.