CA Gov't Code Section 9600

(a)

Except as provided in subdivision (b), a statute enacted at a regular session shall go into effect on January 1 next following a 90-day period from the date of enactment of the statute and a statute enacted at a special session shall go into effect on the 91st day after adjournment of the special session at which the bill was passed.

(b)

Statutes calling elections, statutes providing for tax levies or appropriations for the usual current expenses of the state, and urgency statutes shall go into effect immediately upon their enactment.