Cal. Health & Safety Code § 108956

(a) The online disclosure requirements described in Section 108954.5 shall apply to a designated product sold in the state on or after January 1, 2020.
(b) The product label disclosure requirements described in Section 108954 shall apply to a designated product sold in the state on or after January 1, 2021.
(c) A manufacturer may label a designated product manufactured before January 1, 2021, in accordance with this chapter.
(d) A designated product manufactured prior to the dates specified in subdivisions (a), (b), and (c), shall be deemed in compliance with the requirements of this chapter if the designated product displays either of the following on the designated product:
1. (1) The day, month, and year of manufacture of the product.
2. (2) A code indicating the date described in paragraph (1).
(e) A manufacturer that is required to make a revision to information disclosed online pursuant to Section 108954.5 due to a change in a designated trait list or in Annex III of the EU Cosmetics Regulation No. 1223/2009 as required to be labeled by the EU Detergents Regulation No. 648/2004 shall make the revision no later than six months after the adoption of the revised list by its authoritative body, unless a later effective date for changes is imposed pursuant to the Safe Drinking Water and Toxic Enforcement Act of 1986 (Chapter 6.6 (commencing with Section 25249.5) of Division 20) or Annex III of the EU Cosmetics Regulation No. 1223/2009 as required to be labeled by the EU Detergents Regulation No. 648/2004.
(f) A manufacturer that is required to make a revision to information disclosed on a product label pursuant to Section 108954 due to a change in a designated trait list or in Annex III of the EU Cosmetics Regulation No. 1223/2009 as required to be labeled by the EU Detergents Regulation No. 648/2004 shall make the revision no later than 18 months after the adoption of the revised list by its authoritative body, unless a later effective date for changes is imposed pursuant to the Safe Drinking Water and Toxic Enforcement Act of 1986 (Chapter 6.6 (commencing with Section 25249.5) of Division 20) or Annex III of the EU Cosmetics Regulation No. 1223/2009 as required to be labeled by the EU Detergents Regulation No. 648/2004.
(g) A manufacturer shall make any revision required as a result of a change in the chemical naming protocols set out in Section 108955.5 when it revises its label pursuant to subdivision (f) of this section.
(h) A designated product manufactured prior to the expiration of the time periods described in subdivision (e) or (f) shall be deemed in compliance with this chapter if the designated product displays either of the following on the designated product:
1. (1) The day, month, and year of manufacture of the product.
2. (2) A code indicating the date described in paragraph (1).
(i) If a manufacturer uses a code to indicate the date on the product, the manufacturer shall provide a statement on the manufacturer’s Internet Web site that indicates that the information on the date of manufacture of a designated product may be obtained by calling a toll-free phone number and shall provide the toll-free phone number, or post on the manufacturer’s Internet Web site how to determine the date from the code on the designated product.