California Code, Elections Code - ELEC § 15301

(b)(1) Except as provided in paragraph (2), the canvass shall be continued daily, Saturdays, Sundays, and holidays excepted, for not less than six hours each day until completed.

(2) If the only ballots that the elections official has left to count as part of the official canvass are vote by mail ballots for which a voter has been provided, or will be provided, the opportunity to verify or to provide their signature pursuant to subdivision (d) or (e) of Section 3019, as applicable, and the elections official does not need to conduct the official canvass for at least six hours per day in order to meet the deadline for certification of results pursuant to this section and Section 15372, the official canvass may be conducted for fewer than six hours per day until completed.