Service under a provisional permit shall not be included in computing the service required as a prerequisite to attainment of, or eligibility to, classification as a permanent employee of a child development program. Such persons employed on the effective date of Chapter 1717 of the Statutes of 1965 and who have been employed for three consecutive years prior to the effective date of this legislation shall be deemed to have met the requirements for a regular permit and shall not be subject to the requirements of a provisional permit.