Rev. & Tax. Code, § 75.52

(a) Taxes on the supplemental bill are due on the date mailed and shall become delinquent as follows:

(1) If the bill is mailed within the months of July through October, the first installment shall become delinquent at 5 p.m. on December 10 of the same year. The second installment shall become delinquent at 5 p.m. on April 10 of the next year.

(2) If the bill is mailed within the months of November through June, the first installment shall become delinquent at 5 p.m. on the last day of the month following the month in which the bill is mailed. The second installment shall become delinquent at 5 p.m. on the last day of the fourth calendar month following the date the first installment is delinquent.

(b) If the taxes due are not paid on or before the date and time they become delinquent, a penalty of 10 percent shall attach to them.

(c) The cost enumerated in Section 2621 shall be collected after the second installment is delinquent.

(d) If a delinquent date specified in subdivision (a) falls on a Saturday, Sunday, or legal holiday, the time of delinquency is at 5 p.m. or at the close of business, whichever is later, on the next following business day. If the board of supervisors, by adoption of an ordinance or resolution, closes the county’s offices for business prior to the time of delinquency on the “next business day” or for that whole day, that day shall be considered a legal holiday for purposes of this section.

(e) (1) The penalty imposed for delinquent taxes as provided by this article shall be canceled if the assessee or fee owner demonstrates to the tax collector that the delinquency is due to the tax collector’s failure to mail or electronically transmit the tax bill to the address provided on the tax roll or electronic address provided and authorized by the taxpayer or fee owner to the tax collector. Penalties imposed may be canceled if the board of supervisors, upon recommendation of the tax collector, has authorized the tax collector to establish, and the tax collector has so established, specific procedures for the consideration of penalty cancellations. Those procedures may provide that penalties imposed may be canceled by resolution of the county board of supervisors upon the recommendation of the tax collector if the assessee or fee owner demonstrate to the tax collector that the delinquency is due to the county’s failure to send a notice of taxes to the owner of property acquired after the lien date on the secured roll, provided payment of the amount of taxes due, minus any penalties and costs, is made no later than June 30 of the fiscal year in which the property owner is named as the assessee for taxes coming due.

(2) With respect to a late, amended, or corrected tax bill, the penalties imposed for delinquent taxes shall be canceled if the tax amount is paid within 30 days following the date that bill is mailed or electronically transmitted.

(3) Under no circumstance shall a taxpayer have fewer than 30 days to pay without penalty.