The California Industrial Welfare Commission Wage Orders provide virtually every non-exempt worker in the State of California with the right to an uninterrupted, paid rest period of ten minutes for every four hours of work, or "major fraction thereof." The wage order language is virtually the same for each industry:
(A) Every employer shall authorize and permit all employees to take rest periods, which insofar as practicable shall be in the middle of each work period. The authorized rest period time shall be based on the total hours worked daily at the rate of ten (10) minutes net rest time per four (4) hours or major fraction thereof. However, a rest period need not be authorized for employees whose total daily work time is less than three and one-half (3 ½) hours. Authorized rest period time shall be counted as hours worked for which there shall be no deduction from wages.
(B) If an employer fails to provide an employee a rest period in accordance with the applicable provisions of this Order, the employer shall pay the employee one (1) hour of pay at the employee's regular rate of compensation for each work day that the rest period is not provided.
Contrary to what some managers tell their employees, there is no "restaurant exception." Restaurant workers are covered by the Public Housekeeping Wage Order.
What does a "major fraction thereof" mean? During the first four hours, the wage order itself answers the question. If you worked less than 3 ½, you need not take a break. If you worked more than 3 ½ hours, you get a break. After that, the threshhold is "more than half" of the period. Thus, your second break is earned once your shift is more than two hours into the second four hour period; in other words, after the six-hour mark. A third break is due after the tenth hour of work.