When must a Supreme Court merits amicus file its brief?

For a brief supporting one party, use the date that party’s brief was filed.

For a brief supporting multiple parties, the May 2026 Clerk guide uses the last timely-filed brief of a supported party. Confirm each filing and timeliness rather than using an unsupported late filing.

For a brief supporting neither party, use the end of the time allowed for petitioner’s or appellant’s brief. The Clerk guide expressly applies this regardless of when that brief was actually filed.

Read the docket and any directions establishing the allowed brief date. The calculator does not infer party support, timeliness or the effect of an order.

1. Supporting one party uses its actual brief-filing date. Supporting several uses their last timely-filed brief. Supporting neither uses the petitioner’s or appellant’s allowed filing date, regardless of actual filing.
2. Exclude the established trigger day.
3. Count 7 calendar days.
4. Apply Rule 30.1 final-day adjustment.
5. Complete the required filing by that date.

Supreme Court Rule 30.1 excludes the trigger day and includes every intermediate calendar day. For periods shorter than seven days it excludes intermediate closed days. Each fixed period reviewed here is at least seven days.

Seven days is not shorter than seven days. Rule 30.1 therefore includes intermediate Saturdays, Sundays and holidays. Rule 37.3 does not entertain motions to extend the amicus filing time.

If the final day is Saturday, Sunday, a federal legal holiday listed in 5 U.S.C. 6103 or a Court-building closure ordered by the Court or Chief Justice, Rule 30.1 continues the period to the next day that is none of those. Check actual Court closure orders. The calculator does not infer additional closures.

Fictitious example

Fictitious merits brief filing by the supported party on August 24, 2026. This amicus supports that party, rather than neither party. Exclude the established trigger day, August 24, 2026. Counting 7 calendar days reaches August 31, 2026. The final day is an open weekday.

Fictitious facts and dates. No different schedule, additional Court closure or extension is assumed.

Neutral support changes the trigger

Supporting neither party uses the time allowed for petitioner’s or appellant’s filing, not an earlier actual filing. This can produce a different due date.

Multiple supported parties

The May 2026 Clerk guide uses the last timely-filed brief among supported parties. Establish that the selected filing was timely.

No merits-stage ten-day notice

Rule 37.3 states that Rule 37.2’s ten-day notice requirement does not apply at the oral-argument or Special Master exceptions stage.

No amicus reply or rehearing brief

Rule 37.3 prohibits an amicus reply and an amicus brief supporting or opposing rehearing. This seven-day calculator does not authorize those documents.

Consolidated cases and cover

Identify the supported party or suggested affirmance or reversal on the cover. The Clerk guide gives separate cover and electronic-submission requirements for consolidated and nonconsolidated cases.

• The calculator counts the encoded default period after an established trigger. It does not determine jurisdiction, party alignment or the effect of a particular order.
• Check the Court’s docket, actual directions and proof of the required act.

• Identify which parties, if any, the brief supports.
• Verify the actual supported-party filing, last timely supported filing or allowed petitioner/appellant date.
• Confirm the case is before the Court for oral argument.
• Use the nonextendable seven-day interval and Rule 30.1 final-day adjustment.
• Check admitted counsel, cover position, booklet copies, service proof, compliance certificate and applicable disclosures.
• Rule 29.2 distinguishes timely paper receipt, qualifying USPS postmark, commercial-carrier delivery and proper electronic submission. Under the March 2026 rule, electronic timeliness requires the paper copies to be delivered or mailed by a specified method within three days. Rule 29.7 and the current guidelines impose additional electronic-submission requirements for represented filers and identify exceptions. Filing with the Court does not itself transmit the document to other parties.
• Check represented-filer electronic requirements and paper-copy requirements. The March 2026 guidelines exempt specified sealed and privacy-sensitive filings from electronic submission.
• Preserve both filing and separate service evidence.