California Code, Streets and Highways Code - SHC § 22160

The tax collector shall, within 30 days after the date of delinquency, begin the publication or posting of a notice that the lots or parcels of land upon which the assessments have not been paid will be sold.  The publication shall be made by two consecutive insertions in a daily or weekly newspaper published and circulated in the city.  If there is no such newspaper, the notice shall be given by posting in three public places in the city.