California Code, Elections Code - ELEC § 10700

The Governor shall call all statewide special elections by issuing a proclamation pursuant to Section 12000.Except as provided by Chapter 3 (commencing with Section 10730), in the case of a vacancy in a congressional or legislative office the Governor shall issue a proclamation, within 14 calendar days of the occurrence of the vacancy, calling a special election in accordance with Section 10703. A copy of the proclamation shall be sent to the board of supervisors of each affected county.