(2) in the case of section 314,(a) with respect to employees governed by a collective agreement, an arbitration award in lieu thereof or an order or decree in force on 1 January 1990, from the date of expiry of the agreement or award or from the date of expiry, extension or renewal of the order or decree;
(b) with respect to employees not governed by a collective agreement, an arbitration award or an order or decree referred to in subparagraph a, from 1 January 1990.