This decision holds that a party seeking to vacate an arbitration award must file a petition to vacate or a response (seeking vacatur) to a petition to confirm an arbitration award within 100 days of service of the arbitration award.  (CCP 1288, 1288.2.)  A response seeking to vacate is untimely if filed beyond that 100 day limit even if filed within the separate 10-day deadline (CCP 1290.6) after the opposing party files a petition to confirm.  However, neither of these deadlines is “jurisdictional.”  Something more than a mandatory deadline is required before a statute will be interpreted to deprive courts of fundamental jurisdiction.  Similarly, statutory time deadlines are presumed to be subject to equitable tolling or estoppel unless the Legislature states a clear contrary intention either expressly or by the design or purpose of the statute.  The 100-day arbitration deadline is not jurisdictional and doesn’t preclude extension by equitable tolling or estoppel.  On the other hand, there is no exception to these time deadlines for claims that the arbitration award should be vacated on the ground it enforces an illegal contract.  That basis for vacating an award must be brought within the statutory deadlines for vacating an award or it is forfeited.