California Code, Business and Professions Code - BPC § 7461

An app-based driver shall not be logged in and driving on a network company's online-enabled application or platform for more than a cumulative total of 12 hours in any 24-hour period, unless that driver has already logged off for an uninterrupted period of 6 hours.  If an app-based driver has been logged on and driving for more than a cumulative total of 12 hours in any 24-hour period, without logging off for an uninterrupted period of 6 hours, the driver shall be prohibited from logging back into the network company's online-enabled application or platform for an uninterrupted period of at least 6 hours.