California Code, Labor Code - LAB § 510

(a) Eight hours of labor constitutes a day's work. Any work in excess of eight hours in one workday and any work in excess of 40 hours in any one workweek and the first eight hours worked on the seventh day of work in any one workweek shall be compensated at the rate of no less than one and one-half times the regular rate of pay for an employee. Any work in excess of 12 hours in one day shall be compensated at the rate of no less than twice the regular rate of pay for an employee. In addition, any work in excess of eight hours on any seventh day of a workweek shall be compensated at the rate of no less than twice the regular rate of pay of an employee. Nothing in this section requires an employer to combine more than one rate of overtime compensation in order to calculate the amount to be paid to an employee for any hour of overtime work. The requirements of this section do not apply to the payment of overtime compensation to an employee working pursuant to any of the following:

(b) Time spent commuting to and from the first place at which an employee's presence is required by the employer shall not be considered to be a part of a day's work, when the employee commutes in a vehicle that is owned, leased, or subsidized by the employer and is used for the purpose of ridesharing, as defined in Section 522 of the Vehicle Code.

(c) This section does not affect, change, or limit an employer's liability under the workers' compensation law.