When must an amicus supporting an original-action complaint file its brief?

Identify the original action’s actual Supreme Court docketing date.

Confirm that the amicus supports the plaintiff’s motion for leave to file a bill of complaint. A brief supporting the defendant follows the time allowed for opposition instead.

Counsel of record for every party must receive advance notice under Rule 37.2 unless the brief is filed earlier than ten days before its due date. Timely filing does not automatically prove timely notice.

1. Use Supreme Court docketing. Receipt of the motion by a defendant starts a different opposition procedure.
2. Exclude the established trigger day.
3. Count 60 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.

Rule 37.2 expressly makes the sixty-day filing time nonextendable. Do not add time because a defendant received the pleading later.

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 original-action docketing on August 24, 2026. The amicus supports the plaintiff’s motion for leave to file a bill of complaint. Exclude the established trigger day, August 24, 2026. Counting 60 calendar days reaches October 23, 2026. The final day is an open weekday.

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

Separate advance notice

Rule 37.2 requires all counsel of record to receive notice at least ten days before the brief’s due date unless the brief is filed earlier than ten days before that date. Preserve receipt evidence.

Rule and Clerk guidance wording

The May 2026 Clerk guide describes filing at least ten days before the due date as sufficient notice. The rule uses earlier than ten days. Do not assume filing exactly ten days before clearly satisfies the rule’s exception. Arrange timely actual notice or file more than ten days early.

Attorney and brief requirements

Rule 37.1 requires an attorney admitted to practice before the Court. Follow Rules 33.1 and 37.5–6 for the brief, service proof, compliance certificate and applicable disclosures.

Different position or stage

A brief supporting the defendant follows the opposition period under Rule 37.2. At the Special Master exceptions stage, Rule 37.3 supplies a different seven-day procedure.

• 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.

• Verify actual docketing and support for the plaintiff’s motion.
• Use the nonextendable sixty-day period, not the defendant’s receipt date.
• Arrange advance receipt of notice by all counsel unless the rule’s early-filing exception applies.
• Identify the supported party on the cover and indicate timely notice in the brief.
• Check admitted counsel, 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.