When must California expert exchange be demanded?

The setting of the initial trial and that initial trial date

The seventy-day-before-trial limb alone cannot select the closer of both permitted demand boundaries.

Responsible actor. The party demanding exchange of expert trial-witness information. Establish the date the initial trial was set and the trial date. The demand comparison differs from the later exchange-date comparison. Only the disclosed component is supported. Additional actual closures, altered orders and excluded service methods require separate review.

1. The setting of the initial trial and that initial trial date
2. The seventy-day-before-trial limb alone cannot select the closer of both permitted demand boundaries.
3. Resolve the procedural comparisons described here before selecting an applicable clock. This page supplies no computed or paid date.
4. Make the written demand within the controlling opportunity, identify the demanding party and chapter, and specify the separately determined exchange date.

CCP 12 excludes the triggering day for ordinary day periods. CCP 12a supplies the final judicial-holiday adjustment, including Saturdays and the CCP 135 holidays. CCP 12b addresses qualifying whole-day office closures. Court-day periods exclude intermediate Saturdays, Sundays and judicial holidays. Calendar-day periods include intermediate closed days. Rule 1.11 supplies Friday observance of a Saturday judicial holiday and Monday observance of a Sunday judicial holiday. The calendar includes Lincoln Day, March 31, Juneteenth, Native American Day and Thanksgiving Friday. It excludes Columbus Day and Good Friday as ordinary full judicial holidays. The observed New Year holiday on December 31, 2027 is confirmed in the county schedule. Actual additional closures require separate evidence.

These base components do not add mail, electronic, fax, express or overnight service time. CCP 1013 and 1010.6 identify eligible additions, service conditions and express exceptions. CCP 1005 supplies its own motion-delivery provisions and excludes CCP 1013 for its identified notices. New-trial and CCP 663a intention-notice filings do not receive the stated mail or electronic additions. Establish the actual service method and governing procedure before applying any addition. A summons-service completion event is not determined by the general document-service addition.

The official sections were reviewed, including the retained 2026 and operative-2027 CCP 473 and 415.20 editions. Publication coverage for day and court-day components begins January 1, 2026, or a later expressly stated section effective date. Year components begin no earlier than January 1, 2021, or the section’s later stated effective date, and assume the current reviewed branch applies. These are software coverage boundaries, not findings that an actual act is late. Displayed final dates are confined to the independently reviewed 2026 and 2027 judicial calendar. Closed backward base boundaries and closed minimum-deposition boundaries receive no computed or paid date because their exact adjustment is not implemented. Earlier editions, emergency measures, tolling, different service methods and actual additional closures require separate review.

Assume two cases have the same trial date but that date was initially set on different days. The tenth-day-after-setting limb can produce different demand opportunities.

The existing flagged preset lacks the initial-trial-setting date needed for the closer-to-trial demand comparison. No computed or paid demand date is published.

Demand comparison

The statute compares the tenth day after setting with seventy days before the initial trial and selects the closer-to-trial branch.

Exchange date

CCP 2034.230(b) separately compares fifty days before trial with twenty days after demand service, subject to court ordering.

Service methods and distinct statutory additions

These base components do not add mail, electronic, fax, express or overnight service time. CCP 1013 and 1010.6 identify eligible additions, service conditions and express exceptions. CCP 1005 supplies its own motion-delivery provisions and excludes CCP 1013 for its identified notices. New-trial and CCP 663a intention-notice filings do not receive the stated mail or electronic additions. Establish the actual service method and governing procedure before applying any addition. A summons-service completion event is not determined by the general document-service addition.

Edition and calendar coverage

The official sections were reviewed, including the retained 2026 and operative-2027 CCP 473 and 415.20 editions. Publication coverage for day and court-day components begins January 1, 2026, or a later expressly stated section effective date. Year components begin no earlier than January 1, 2021, or the section’s later stated effective date, and assume the current reviewed branch applies. These are software coverage boundaries, not findings that an actual act is late. Displayed final dates are confined to the independently reviewed 2026 and 2027 judicial calendar. Closed backward base boundaries and closed minimum-deposition boundaries receive no computed or paid date because their exact adjustment is not implemented. Earlier editions, emergency measures, tolling, different service methods and actual additional closures require separate review.

• Establish the date the initial trial was set and the trial date. The demand comparison differs from the later exchange-date comparison. Only the disclosed component is supported. Additional actual closures, altered orders and excluded service methods require separate review.
• The existing flagged preset lacks the initial-trial-setting date needed for the closer-to-trial demand comparison. No computed or paid demand date is published.

• The setting of the initial trial and that initial trial date
• The seventy-day-before-trial limb alone cannot select the closer of both permitted demand boundaries.
• The statute compares the tenth day after setting with seventy days before the initial trial and selects the closer-to-trial branch.
• CCP 2034.230(b) separately compares fifty days before trial with twenty days after demand service, subject to court ordering.
• Make the written demand within the controlling opportunity, identify the demanding party and chapter, and specify the separately determined exchange date.
• Where filing is required, distinguish accepted filing from service. CCP 1010.6(e)(3) gives the stated same-court-day treatment to qualifying electronic court receipt between 12:00 a.m. and 11:59:59 p.m.; noncourt-day receipt is deemed on the next court day. Its confirmation and rejection provisions still matter. Preserve the accepted filing confirmation, effective service evidence and applicable local requirements. Court-office paper availability and case-specific orders require separate review. This does not turn a service-only response, court determination, completed discovery or trial commencement into a filing-only act.