California Codes, Civil Code - CIV, Preliminary Provisions, Section 3
No part of it is retroactive, unless expressly so declared.
Notes
Bars any part of the code from operating retroactively unless retroactive effect is expressly declared. Sets a default rule of prospective application only, so a provision reaches back in time only where the enacting language itself says so, and not by implication.
Use as reference
Lexinter.net | California Code, Civil Code - CIV § 3 | https://laws.lexinter.net/codes/california/civil-code/preliminary-provisions/section-3