47 C.F.R. § 78.29
Licenses for CARS stations will be issued for a period not to exceed five (5) years. On and after February 1, 1966, licenses for CARS stations ordinarily will be issued for a period expiring on February 1, 1971, and, when regularly renewed, at 5-year intervals thereafter. When a license is granted subsequent to the last renewal date for CARS stations, the license will be issued only for the unexpired period of the current license term of such stations. The license renewal date applicable to CARS stations may be varied as necessary to permit the orderly processing of renewal applications, and individual station licenses may be granted or renwed for a shorter period of time than that generally prescribed for CARS stations, if the Commission finds that the public interest, convenience, and necessity would be served by such action.
47 C.F.R. §78.29