California Code, Elections Code - ELEC § 9145

If the board of supervisors does not entirely repeal the ordinance against which a petition is filed, the board shall submit the ordinance to the voters either at the next regularly scheduled county election occurring not less than 88 days after the date of the order, or at a special election called for that purpose not less than 88 days after the date of the order. The ordinance shall not become effective unless and until a majority of the voters voting on the ordinance vote in favor of it.