30-day notice terminating month-to-month tenancy (Civ. Code 1946): earliest termination date

as to tenancies from month to month either of the parties may terminate the same by giving at least 30 days’ written notice thereof at any time and the rent shall be due and payable to and including the date of termination

CCP 12: "The time in which any act provided by law is to be done is computed by excluding the first day, and including the last, unless the last day is a holiday, and then it is also excluded." CCP 12a(a): "If the last day for the performance of any act provided or required by law to be performed within a specified period of time is a holiday, then that period is hereby extended to and including the next day that is not a holiday. For purposes of this section, “holiday” means all day on Saturdays, all holidays specified in Section 135 and, to the extent provided in Section 12b, all days that by terms of Section 12b are required to be considered as holidays." CCP 12b: "If any city, county, state, or public office, other than a branch office, is closed for the whole of any day, insofar as the business of that office is concerned, that day shall be considered as a holiday for the purposes of computing time under Sections 12 and 12a." CCP 10: "Holidays within the meaning of this code are every Sunday and any other days that are specified or provided for as judicial holidays in Section 135."