35 U.S.C. § 21
Section 21 · Filing date and day for taking action
This is the Bayh-Dole Act of 1980
Amended 4 times on record
Applied in 12 court decisions — leading case Aqua Products, Inc. v. Matal (2017)
Most recently applied in Aqua Products, Inc. v. Matal (October 2017)
How often courts cite this section
Court decisions citing this, by year.Markers show enactment, consequential amendments, and circuit splits over this section — watch for a citation surge after a change or a disagreement. The dip in the last several years is a data-coverage gap, not a real trend — our corpus holds fewer opinions from the most recent years, so recent citations are undercounted.
(a) The Director may by rule prescribe that any paper or fee required to be filed in the Patent and Trademark Office will be considered filed in the Office on the date on which it was deposited with the United States Postal Service or would have been deposited with the United States Postal Service but for postal service interruptions or emergencies designated by the Director.
(b) When the day, or the last day, for taking any action or paying any fee in the United States Patent and Trademark Office falls on Saturday, Sunday, or a Federal holiday within the District of Columbia, the action may be taken, or the fee paid, on the next succeeding secular or business day.
Editorial notes U.S. Code · Office of the Law Revision Counsel
Historical and Revision Notes
Based on Title 35, U.S.C., 1946 ed., §21 (Mar. 2, 1927, ch. 273, §14, 44 Stat. 1337).
“Fixed by statute” is omitted from the corresponding section of the existing statute as unnecessary. Saturday is added as a day on which action need not be taken.
Amendments
1999—Subsec. (a). Pub. L. 106–113 substituted “Director” for “Commissioner” in two places.
1982—Pub. L. 97–247 substituted “Filing date and day for taking action” for “Day for taking action falling on Saturday, Sunday, or holiday” as section catchline, added subsec. (a), redesignated existing provisions as subsec. (b) and inserted “Federal” after “Sunday, or a”.
1975—Pub. L. 93–596 substituted “Patent and Trademark Office” for “Patent Office”.
Effective Date of 1999 Amendment
Amendment by Pub. L. 106–113 effective 4 months after Nov. 29, 1999, see section 1000(a)(9) [title IV, §4731] of Pub. L. 106–113, set out as a note under section 1 of this title.
Effective Date of 1982 Amendment
Amendment by Pub. L. 97–247 effective six months after Aug. 27, 1982, see section 17(c) of Pub. L. 97–247, set out as an Effective Date note under section 294 of this title.
Effective Date of 1975 Amendment
Amendment by Pub. L. 93–596 effective Jan. 2, 1975, see section 4 of Pub. L. 93–596, set out as a note under section 1111 of Title 15, Commerce and Trade.
Emergency Relief From Postal Situation Affecting Patent Cases
Relief as to filing date of patent application or patent and excusal of delayed fees or actions affected by postal situation beginning on Mar. 18, 1970, and ending on or about Mar. 30, 1970, see note set out under section 111 of this title.
Cross References
Federal holidays, see section 6103 of Title 5, Government Organization and Employees.