An employer that makes contributions to a multiemployer plan as described in section 3(7)(b) shall not require an employee to wait until 120 calendar days after commencing employment with that employer before using unused accrued earned sick time and nonforfeited paid sick leave benefits that were earned as a result of past service for a different employer that also made contributions to the same multiemployer plan or any paid sick leave benefits earned by working under the collective bargaining agreement for that employer. Contributions required under the collective bargaining agreement or other employment agreement for the paid sick leave plan are due on the same schedule as the other fringe benefit funds or plans to which the signatory employer must contribute.