A California 3-day notice to quit for non-payment is a document served to a tenant who has not paid their rent on time. California law does not require landlords to provide a grace period for their tenants, but they may do so as long as it is included in the lease agreement. Assuming the landlord does not provide a grace period, they would be able to deliver this 3-day notice to pay or quit the day after the rent due date. The tenant, upon receiving the notice, must either pay the full amount or vacate the premises within three days, otherwise; they risk the landlord filing an eviction suit against them.
Laws – § 1161(2)
When is Rent Due? (§ 1947) – Rent is due at the end of the month (for leases of one year or less) if a lease agreement does not mention a due date. Typically, landlords stipulate in the agreement that rent is due at the beginning of the month.