Business Days Calculator

Background.

This business days calculator counts the actual number of US working days between two dates — Monday-through-Friday weekdays, with all 11 US federal holidays optionally excluded. It exists to close the gap left by simpler date-difference tools: a plain weekday count treats every Monday through Friday as a workday, but real payroll periods, court filing deadlines, shipping ETAs, and contract deliverables are built around actual federal business days, where a Thanksgiving Thursday or a Fourth-of-July Friday does not count even though it falls on a weekday.

The 11 US federal holidays are computed from their statutory rules for whichever years your date range touches, never hardcoded from a lookup table for a single year. Five are fixed calendar dates — New Year's Day (January 1), Juneteenth National Independence Day (June 19, a federal holiday since the Juneteenth National Independence Day Act was signed on June 17, 2021), Independence Day (July 4), Veterans Day (November 11), and Christmas Day (December 25). Six are floating, defined relative to a weekday rather than a date — the Birthday of Martin Luther King, Jr. (third Monday of January), Washington's Birthday, commonly called Presidents' Day (third Monday of February), Memorial Day (last Monday of May), Labor Day (first Monday of September), Columbus Day (second Monday of October), and Thanksgiving Day (fourth Thursday of November). Because the six floating holidays are defined by weekday, they can never themselves fall on a weekend; the five fixed-date holidays can, and when one does, the U.S. Office of Personnel Management's observed-holiday rule shifts it: a holiday landing on a Saturday is observed the preceding Friday, and one landing on a Sunday is observed the following Monday. This calculator applies that exact shift before checking whether a holiday falls inside your date range, so a Fourth of July that lands on a Saturday correctly removes the Friday before it, not the weekend day that was already excluded from the weekday count.

The holiday exclusion is a toggle, not a fixed behavior, because 'business days' means different things to different audiences. A US federal contractor needs the full 11-holiday exclusion. A retail operation that stays open on most federal holidays except Thanksgiving and Christmas needs a different subtraction entirely — for that case, switch the toggle off, read the plain weekday count, and subtract your own smaller holiday list by hand. International users whose local public holidays differ entirely from the US federal calendar should also turn the toggle off and apply their own country's holiday count separately, exactly as `date-difference`'s own FAQ recommends.

As with every date calculator on this site, all arithmetic is performed at UTC midnight rather than local time, so daylight-saving-time transitions cannot inject or remove a phantom day at the boundary — the same UTC-anchoring discipline used throughout `date-difference` and `age-calculator`.

What is business days calculator?

A business day (or working day) is, in the US federal context, any Monday through Friday that is not one of the 11 federal holidays designated under 5 U.S.C. § 6103. The federal holiday schedule is published and administered by the U.S. Office of Personnel Management (OPM), which also governs what happens when a fixed-date holiday falls on a weekend: if it falls on a Saturday, most federal employees observe the preceding Friday as the holiday; if it falls on a Sunday, they observe the following Monday. This 'observed date' — not the calendar date printed on a wall calendar — is the day banks, courts, the postal service, and most federal offices actually close, and it is the date this calculator excludes from the business-day count. Six of the eleven federal holidays are already pinned to a specific weekday by their statutory definition (for example, Labor Day is 'the first Monday in September', not 'September 1') and therefore never require the weekend-observed shift at all; only the five holidays with a fixed calendar date — New Year's Day, Juneteenth, Independence Day, Veterans Day, and Christmas — can land on a weekend and need the shift applied.

How to use this calculator.

1. 01Enter the earlier date in 'Start date' and the later date in 'End date', both in ISO 8601 format (YYYY-MM-DD).
2. 02Choose whether the end date itself should count as a business day if it happens to be a weekday (inclusive) or should be treated as the boundary you count up to (exclusive, the default).
3. 03Leave 'Exclude US federal holidays' set to Yes for the standard US federal business-day count, or switch it to No if you want the plain weekday count with holidays reported separately but not subtracted.
4. 04Read the primary 'Business days' figure for your answer. Check 'Weekdays (Mon-Fri)' and 'Federal holidays in range' beneath it to see exactly how the total was built.
5. 05If your organization observes a different or smaller holiday list than the full federal 11, turn the exclusion toggle off, take the weekday figure, and subtract your own holiday count by hand.

The formula.

The calculator runs four steps.

1. Weekday count. It iterates every calendar day from the start date up to (but not including, unless the inclusive toggle is on) the end date and counts every day whose UTC day-of-week is Monday through Friday.

2. Holiday generation. For every calendar year the date range touches, it computes all 11 US federal holidays from their rules rather than a lookup table: five fixed-date holidays (New Year's Day Jan 1, Juneteenth Jun 19, Independence Day Jul 4, Veterans Day Nov 11, Christmas Dec 25) and six floating holidays defined as the Nth or last occurrence of a weekday in a month (MLK Day: 3rd Monday of January; Washington's Birthday: 3rd Monday of February; Memorial Day: last Monday of May; Labor Day: 1st Monday of September; Columbus Day: 2nd Monday of October; Thanksgiving: 4th Thursday of November).

3. Weekend-observed shift. Only the five fixed-date holidays can fall on a weekend (the floating ones are pinned to a weekday by definition). Per OPM guidance, a holiday that falls on a Saturday is observed the preceding Friday; one that falls on a Sunday is observed the following Monday. The calculator applies this shift before checking whether the holiday lies inside the requested date range.

4. Subtraction. It counts how many of the (already weekend-shifted) holiday dates fall inside the range and, if the exclusion toggle is on, subtracts that count from the raw weekday total. If the toggle is off, the count is still reported (so you can see what would be excluded) but is not subtracted from the primary result — this keeps the output shape identical regardless of the toggle, rather than making the toggle change which fields appear.

A worked example.

Frequently asked questions.

References& sources.

1. [1]U.S. Office of Personnel Management. Federal Holidays. Official schedule, rules, and the weekend-observed-date policy for all 11 US federal holidays.
2. [2]5 U.S.C. § 6103 — Holidays. The federal statute enumerating the legal public holidays observed by the United States government.
3. [3]Juneteenth National Independence Day Act, Public Law 117-17 (June 17, 2021). Established June 19 as the 11th US federal holiday.
4. [4]International Organization for Standardization, ISO 8601-1:2019 — Date and time representations. The YYYY-MM-DD format this calculator's date inputs follow.