37 CFR § 11.4 - Computing time.

Computing time. The following rules apply in computing any time period specified in this part where the period is stated in days or a longer unit of time:

(a) Exclude the day of the event that triggers the period;

(b) Count every day, including intermediate Saturdays, Sundays, and legal holidays; and

(c) Include the last day of the period, but if the last day is a Saturday, Sunday, or legal holiday, the period continues to run until the end of the next day that is not a Saturday, Sunday, or legal holiday.

[86 FR 28452, May 26, 2021]