Ending month to month tenancy in CA

[Fernan Nava]

Hey guys out here in CA, have a tenant that’s been renting from me for bout 14 months the lease expired a couple of months ago and she’s been on a month to month lease since then. Anyway,I trained her the wrong way and she is a serious late payer, she’s gonna be getting a 60 day notice very soon. My question is when does the 60 day notice start running, when I mail it , when she gets it or from the 1st when the rent period begins? If you know the answer sure would like to hear it. Thanks.