The general “extension rule” of CCP 12a which does apply to 3 Day Notices, does NOT apply to exercise of lease options. In a commercial lease, the civil procedure rule extending period to perform any lawfully required act past holidays, including Saturday, to next non-holiday did not apply to lease between commercial tenants and landlords, so the tenants’ attempt to exercise lease option was untimely, although last day to exercise option fell on Saturday and tenants attempted to exercise option the following Monday. The Court held: “Its omission of the contract language from Code of Civil Procedure section 12a, while using that language in Civil Code sections 9 and 11, evidences an intent to exclude contracts from the purview of that section. For this reason, we hold that Code of Civil Procedure section 12a does not apply to acts governed solely by contractual provisions. Accordingly, section 12a did not apply to extend the time in which plaintiffs could exercise their option to extend their lease. Gans v. Smull (2003) 111 Cal.App.4th 985, 990