Subdivision Map Act challenge: commence action and effect service of summons within 90 days after the decision
90 days after date of the advisory agency, appeal board, or legislative body decision concerning the subdivision, under Cal. Gov. Code 66499.37.
Rule text
Any action or proceeding to attack, review, set aside, void, or annul the decision of an advisory agency, appeal board, or legislative body concerning a subdivision, or of any of the proceedings, acts, or determinations taken, done, or made prior to the decision, or to determine the reasonableness, legality, or validity of any condition attached thereto, including, but not limited to, the approval of a tentative map or final map, shall not be maintained by any person unless the action or proceeding is commenced and service of summons effected within 90 days after the date of the decision. Thereafter all persons are barred from any action or proceeding or any defense of invalidity or unreasonableness of the decision or of the proceedings, acts, or determinations.
Calculate this deadline
Deadline
Thursday, February 4, 2027
- Trigger (Date of the advisory agency, appeal board, or legislative body decision concerning the subdivision): Friday, November 6, 2026.
- Exclude the trigger day and count 90 calendar days: Thursday, February 4, 2027.
Rules applied
Cal. Gov. Code 66499.37
Any action or proceeding to attack, review, set aside, void, or annul the decision of an advisory agency, appeal board, or legislative body concerning a subdivision, or of any of the proceedings, acts, or determinations taken, done, or made prior to the decision, or to determine the reasonableness, legality, or validity of any condition attached thereto, including, but not limited to, the approval of a tentative map or final map, shall not be maintained by any person unless the action or proceeding is commenced and service of summons effected within 90 days after the date of the decision. Thereafter all persons are barred from any action or proceeding or any defense of invalidity or unreasonableness of the decision or of the proceedings, acts, or determinations.Official source
Cal. Code Civ. Proc. 12, 12a, 12b; Cal. Gov. Code 6800, 6707 (state agency filings); Fed. R. Civ. P. 6(a) (federal statutes and federal court filings)
CCP 12: "The time in which any act provided by law is to be done is computed by excluding the first day, and including the last, unless the last day is a holiday, and then it is also excluded." CCP 12a(a): "If the last day for the performance of any act provided or required by law to be performed within a specified period of time is a holiday, then that period is hereby extended to and including the next day that is not a holiday. For purposes of this section, “holiday” means all day on Saturdays, all holidays specified in Section 135 and, to the extent provided in Section 12b, all days that by terms of Section 12b are required to be considered as holidays." Gov. Code 6707: "When the last day for filing any instrument or other document with a state agency falls upon a Saturday or holiday, such act may be performed upon the next business day with the same effect as if it had been performed upon the day appointed." FRCP 6(a): "The following rules apply in computing any time period specified in these rules, in any local rule or court order, or in any statute that does not specify a method of computing time. (1) ... (A) exclude the day of the event that triggers the period; (B) count every day, including intermediate Saturdays, Sundays, and legal holidays; and (C) include the last day of the period, but if the last day is a Saturday, Sunday, or legal holiday, the period continues to run until the end of the next day that is not a Saturday, Sunday, or legal holiday."Official source
- Both filing and SERVICE OF SUMMONS within 90 days. Also bars defenses of invalidity after the period. Fee and exaction protests on subdivisions may also be governed by Gov. Code 66020 (separate rules). Roll assumes CCP 12a.
- If the clerk's office is closed or inaccessible on the last day (weather, emergency or local closure orders), the deadline may be extended. Check local orders.
This calculator applies the cited rules to the dates you enter. It is not legal advice. Court orders, local rules, and case-specific facts can change a deadline; verify before relying on it. Rule set pending attorney review.
Worked example
Date of the advisory agency, appeal board, or legislative body decision concerning the subdivision on Monday, March 15, 2027, personal service: due Monday, June 14, 2027.
- Trigger (Date of the advisory agency, appeal board, or legislative body decision concerning the subdivision): Monday, March 15, 2027.
- Exclude the trigger day and count 90 calendar days: Sunday, June 13, 2027.
- That day is a Sunday, so the deadline moves to the next court day: Monday, June 14, 2027 (Cal. Code Civ. Proc. 12, 12a, 12b; Cal. Gov. Code 6800, 6707 (state agency filings); Fed. R. Civ. P. 6(a) (federal statutes and federal court filings)).
Notes
Both filing and SERVICE OF SUMMONS within 90 days. Also bars defenses of invalidity after the period. Fee and exaction protests on subdivisions may also be governed by Gov. Code 66020 (separate rules). Roll assumes CCP 12a.
Related deadlines
- Challenge to general/specific plan, zoning ordinance, development agreement, variance, CUP or permit condition: commence AND serve legislative body within 90 days after decision (90 days after)
- Housing element challenge: additional window, commence and serve within 60 days after HCD reports its findings (60 days after)
- Coastal Commission decision or action: petition for writ of mandate (CCP 1094.5) within 60 days after the decision becomes final (60 days after)
- Housing Accountability Act: file and serve petition within 90 days from effective date of local agency decision (alternative 1) (90 days after)
- Housing Accountability Act: file and serve petition within 90 days from expiration of the 65589.5(h)(5)(B) time periods (alternative 2) (90 days after)
- Action to enforce zoning consistency with general plan (Gov. Code 65860): commence AND serve legislative body within 90 days (90 days after)
- Mitigation Fee Act: protest fees, dedications or exactions within 90 days after imposition (or at approval) (90 days after)
- Mitigation Fee Act: action to set aside fees or exactions within 180 days after delivery of the agency's notice (180 days after)
Rules current as of 2026-10-27. Confirm against the official source and any local rule or court order before relying on a date. Rules changelog.