For the purpose of this title, completion of a work of improvement occurs at the earliest of the following times:

1. (a) Acceptance of the work of improvement by the public entity.
2. (b) Cessation of labor on the work of improvement for a continuous period of 60 days. This subdivision does not apply to a contract awarded under the State Contract Act, Part 2 (commencing with Section 10100) of Division 2 of the Public Contract Code.