Code of Civil Procedure § 415.10

415.10.

A summons may be served by personal delivery of a copy of the summons and of the complaint to the person to be served. Service of a summons in this manner is deemed complete at the time of such delivery.

The date upon which personal delivery is made shall be entered on or affixed to the face of the copy of the summons at the time of its delivery. However, service of a summons without such date shall be valid and effective.