When must a Delaware briefing extension motion be docketed?

A first-extension motion must ordinarily be docketed at least five days before the brief or appendix due date. Count backward from the actual due date. Because five is shorter than seven, Rule 11(a) excludes intermediate Saturdays, Sundays and legal holidays.

Responsible actor. The participant seeking a first briefing extension.

Establish the actual brief or appendix deadline.

Obtain the opponent’s position or document diligent attempts.

Complete the motion and arrange docketing with the required five-day lead.

Use the established current filing deadline as the anchor, not the proposed extended deadline. The calculator supplies the ordinary minimum lead-time component, not permission to extend.

1. The actual existing due date for the brief or appendix
2. Count five earlier eligible days from the established briefing due date. Rule 11(a) excludes intermediate Saturdays, Sundays and legal holidays because five is less than seven.
3. Docket a motion substantially in Official Form F. State the opponent’s position or explain diligent efforts to obtain it. Preserve the motion receipt and the later order granting or refusing relief.

Rule 11(a) excludes the event day. A prescribed period below seven days excludes intermediate Saturdays, Sundays and legal holidays. Seven days and longer count those intermediate days. A final Saturday, Sunday, legal holiday or actual Clerk closure receives the stated next-open-day treatment. A backward five-day motion component counts earlier eligible days to preserve its required lead. Do not apply the separate Chancery or Superior Court eleven-day threshold.

The 2026 named calendar follows the Court’s published statewide holidays. The 2027 dates are projections of 1 Del. C. § 501 and its fixed-holiday observation rule. December 31, 2027 is the observed New Year holiday for Saturday, January 1, 2028. These dates do not confirm future amendments, Governor or Chief Justice appointments or actual additional closures. Sussex Return Day afternoon is not treated as a statewide full-day Supreme Court closure. Review any actual additional closure separately.

Rule 11(c) adds three days to a participant’s prescribed period after incoming service by mail or eFiling. Personal service adds none. The addition enters the period before Rule 11(a) counting and final-day treatment. It does not apply to Court acts or to an entry, filing, issuance or acceptance event merely because a copy is served. Rule 10(b) completes mail service on mailing. Rule 10.1(h) treats authorized electronic service like mail for the addition. A convenience email notification under Rule 10.2(6)(d) is not the service event.

Reviewed coverage uses the retained Supreme Court compilation current through February 2, 2026, for established events on or after that compilation boundary and final dates through December 31, 2027. The index label is not a new effective date for every civil rule. Historical events, backward periods crossing that boundary, later dates, changed orders and actual additional closures require separate review. No computed or paid date is supplied for an input outside that coverage. This boundary does not establish that an actual act is late.

Fictitious example

Fictitious established current-edition event. Personal service where the period runs from service. No altered order or additional closure.

Fictitious established facts. The example does not establish applicability, actual service, completed filing, an extension, entitlement or a special closure. Use the established current filing deadline as the anchor, not the proposed extended deadline. The calculator supplies the ordinary minimum lead-time component, not permission to extend.

Exceptional late request

Under Rule 15(b)(iv), a shorter lead ordinarily fails unless exceptional circumstances support both the extension and late motion.

After the brief is due

Rule 15(b)(vi) limits post-deadline relief to the interests-of-justice exception and a maximum three-day extension. This calculator does not grant that relief.

Approval still required

Rule 15(b) discourages extensions and distinguishes Clerk and Justice authority. An unopposed request is not automatically an approved new deadline.

Participant service and Court acts

Rule 11(c) adds three days to a participant’s prescribed period after incoming service by mail or eFiling. Personal service adds none. The addition enters the period before Rule 11(a) counting and final-day treatment. It does not apply to Court acts or to an entry, filing, issuance or acceptance event merely because a copy is served. Rule 10(b) completes mail service on mailing. Rule 10.1(h) treats authorized electronic service like mail for the addition. A convenience email notification under Rule 10.2(6)(d) is not the service event.

Compilation and calendar coverage

Reviewed coverage uses the retained Supreme Court compilation current through February 2, 2026, for established events on or after that compilation boundary and final dates through December 31, 2027. The index label is not a new effective date for every civil rule. Historical events, backward periods crossing that boundary, later dates, changed orders and actual additional closures require separate review. No computed or paid date is supplied for an input outside that coverage. This boundary does not establish that an actual act is late.

• Use the established current filing deadline as the anchor, not the proposed extended deadline. The calculator supplies the ordinary minimum lead-time component, not permission to extend.
• The stated component does not obtain an extension, establish completed acts or decide an excluded procedural branch.

• Establish the actual brief or appendix deadline.
• Obtain the opponent’s position or document diligent attempts.
• Complete the motion and arrange docketing with the required five-day lead.
• Under Rule 15(b)(iv), a shorter lead ordinarily fails unless exceptional circumstances support both the extension and late motion.
• Rule 15(b)(vi) limits post-deadline relief to the interests-of-justice exception and a maximum three-day extension. This calculator does not grant that relief.
• Rule 15(b) discourages extensions and distinguishes Clerk and Justice authority. An unopposed request is not automatically an approved new deadline.
• For the paper participants described in Rule 10, serve the required recipients and complete filing by actual Clerk or Deputy Clerk receipt during regular business hours. Mailing a filing on the final day does not establish receipt. Registered eFiling under Rules 10.1 and 10.2 uses the recorded completed transaction. In nonexpedited cases, ordinary electronic filings must finish by 5 p.m. Eastern Time. Notices of appeal and electronic filings in expedited cases must finish before midnight Eastern Time. Electronic service requires selection of recipients and submission through File & Serve. Preserve the receipt identifying date, time, method and recipients. The email notification alone is not service. Rule 10.2(10) permits relief for specified filing or service errors only upon satisfactory proof and a Court order; no automatic extension is calculated.