Cal. Lab. Code § 1142.5

(a) The board shall maintain, at its principal office, a telephone line 24 hours a day, seven days a week, for the purpose of providing interested persons with information concerning their rights and responsibilities under this part, or for referring such persons to the appropriate agency or entity with the capacity to render advice or help in dealing with any situation arising out of agricultural labor disputes.
In order to carry out its responsibilities pursuant to this subdivision, the board may contract with an answering service to receive telephone messages during periods of time that its principal office is normally not open for business. Such messages shall be transmitted to the board on the board’s next business day, or at such earlier time as the board specifies, or to its designated representative at the earliest possible time.
(b) Whenever a petition for an election has been filed in a bargaining unit in which a majority of the employees are engaged in a strike, the necessary and appropriate services of the board in the region in which the election will be held shall be available to the parties involved 24 hours a day until the election is held.