Cal. Bus. & Prof. Code § 21715.5

The owner may, upon the expiration of a period of at least 30 days from giving notice in writing to the occupant by personal delivery, by first-class mail, postage prepaid, to the last known address of the occupant, or by email pursuant to subdivision (c) of Section 21712, change the terms of the rental agreement. The notice, upon the expiration of a period of at least 30 days from the date of service, shall in and of itself operate and be effectual to create and establish, as a part of the rental agreement, the terms, rents, and conditions specified in the notice, if the occupant continues to store personal property at the self-service storage facility after the notice takes effect.