Bid Advertisement Date: Which Prevailing Wage Determination Applies?

On a California public works project, every prevailing wage question eventually comes back to one date: the day the job was first advertised for bids. That date, not the award date, not the contract start date, not the day your crew shows up, decides which DIR wage determination governs the project. Get it wrong and every rate on your certified payroll can be wrong with it.

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What counts as the bid advertisement date

California regulation defines the bid advertisement date as the date the first notice inviting bids was published in a newspaper of general circulation, or otherwise promulgated in a legally sufficient manner (8 CCR section 16000). It is usually printed in the Notice to Bidders inside the contract documents. For Caltrans contracts, the Office of Engineer page for the contract number lists both the advertisement date and the bid opening date.

The two dates contractors most often substitute for it, the award date and the contract start date, are usually months later. Caltrans's own Labor Compliance Manual puts it plainly: the bid advertisement date establishes the applicable general prevailing wage determination version for a project.

The calendar: issued twice a year, effective ten days later

DIR issues its general prevailing wage determinations twice a year, on February 22nd and August 22nd. Each issuance takes effect ten days after the issue date (8 CCR section 16204). DIR spells out what that means on its determination index pages: the February issuance takes effect March 3rd in a leap year and March 4th in a non-leap year, and the August issuance takes effect September 1st.

The regulation then connects the calendar to your project: any call for bids put out on or after the effective date of a determination must reflect that determination. Advertised before the effective date, and the prior issuance governs.

One day can change the answer

We recently worked through a real example with a CPA whose client holds a contract with a state awarding body. The agency confirmed the bid advertisement date: March 3rd, 2026. The 2026 first-half determinations were issued February 22nd, 2026, and 2026 is not a leap year, so they took effect March 4th, 2026. The advertisement went out one day before that. The project is therefore governed by the prior issuance, the 2025-2 rate books, for its entire life.

In that particular case the answer was forgiving: the craft's determination carried the same number and the same rate in both books, so either side of the line produced the same wage. You cannot count on that. When a determination steps up between issuances, one day of advertisement timing is the difference between the old rate and the new one on every hour of the job.

The asterisks: whether your rate is locked

Every determination prints an expiration date, and what happens at that date depends on the mark next to it.

• Single asterisk: DIR's FAQ states that determinations with a single asterisk after the expiration date, which are in effect on the date of advertisement for bids, remain in effect for the life of the project. The rate you started with is the rate for the whole job, even if later books show a higher one.
• Double asterisk: the rate has a predetermined increase already set. If work extends past the expiration date, you must pay the new rate from that date forward, even though the determination that governs the project has not changed.

This is where contractors overpay or underpay without noticing. A single-asterisk determination means no mid-project catch-up is owed when a new book publishes higher figures. A double-asterisk determination means the increase is owed automatically, with no new advertisement required. We break both marks down with the mistakes each one causes in our asterisk guide.

What to do with this on your certified payroll

• Get the bid advertisement date in writing from the Notice to Bidders or the awarding body, and keep it in the project file.
• Pull the determination that was in effect on that date, and record its full number. That number is what belongs on forms that ask which determination applies.
• Check the asterisk before honoring any rate change mid-project.
• Save the determination PDF itself. Determinations are superseded on the DIR site twice a year, and an auditor wants the version that governed your job.

The rates on the determination feed straight into your weekly reporting: base, fringe, training fund, and the overtime math built from the basic rate. Our free prevailing wage calculator does the base, fringe, and overtime arithmetic for you, and the California certified payroll page covers how DIR reporting works end to end.