California Code, Streets and Highways Code - SHC § 18062

The city council shall, in the resolution of intention, provide that the improvement of the street lighting system shall be for a period of time stated in the resolution of intention.  The dates of commencement and ending of that period shall be fixed by the city council on or before the date of execution of any contract as provided in this part, or, in the event that no contract is let and the maintenance or servicing is furnished by the city, those dates shall be fixed by the city council on or before the date of ordering the maintenance or servicing by the city.  The city council may subsequently postpone the dates of commencement and ending of the period for a reasonable time upon good and sufficient reason appearing therefor and may, in any advertisement for bids and in any contract entered into, reserve the right to make such postponement for such reason.