California Code, Civil Code - CIV § 9204

(a) A public entity may record a notice of completion on or within 15 days after the date of completion of a work of improvement.

(b) The notice shall be signed and verified by the public entity or its agent.

(c) The notice shall comply with the requirements of Chapter 2 (commencing with Section 8100) of Title 1, and shall also include the date of completion.  An erroneous statement of the date of completion does not affect the effectiveness of the notice if the true date of completion is 15 days or less before the date of recordation of the notice.