P1 · Working-day countNo hidden counting rules.

Business Days Calculator

Count working days in a date range without hiding the choices that matter: endpoint inclusion, weekend pattern and whether observed U.S. federal holidays are removed.

Universal engineBusiness Days CalculatorFree · local-first · explicit assumptions
Reference calculation

Enter your details.

Calculated locally in your browser. Nothing is uploaded to CalcSpan.

Switch modes without leaving the page. Each result states its counting convention.
Sun, Aug 23, 2026
Tue, Sep 22, 2026
This is not an employer, court, exchange, state or local closure calendar.

Plain-date semantics · start date is not counted unless the result explicitly says inclusive.

Your result
21 business days

Start excluded; end included. Saturday and Sunday and current U.S. federal holidays are excluded.

StartAug 23, 2026 · Sunday
EndSep 22, 2026 · Tuesday
Business days21
Calendar boundaries30 days
Calendar dates evaluated30After the selected endpoint rules.
Weekend dates excluded8Saturday and Sunday
Holiday dates excluded1Sep 7, 2026 — Labor Day
Endpoint ruleExclude start · Include end

Read before relying

Context matters.

  • The U.S. federal option follows the current statutory holiday pattern and normal Friday/Monday observance for fixed-date holidays.
  • It is not a historical calendar and does not include one-off executive closures, inauguration day, state holidays, local holidays, exchange holidays or an employer's own schedule.
Rule set 2.0.0

Sources & scope

Source & calculation QA reviewed

The calculation guide and this source trail show what the result means, where the rule came from and when it was last reviewed. This is source-and-calculation QA, not a claim of medical, legal, tax or other professional review; time-sensitive decisions still belong with the linked authority.

JurisdictionGlobal Gregorian date arithmetic and IANA time zones; optional U.S. federal holiday planning calendar
Last reviewed2026-08-22
Next review due2027-02-22
Review scopeCalcSpan source & calculation QA
PrivacyNo input upload
How it works

A business-day count with no invisible convention.

The tool first applies the selected endpoint rule, then removes weekend dates and eligible holiday dates. Every exclusion count remains visible in the result.

  1. 01Set the range

    Choose a start date and an end date in chronological order.

  2. 02Choose endpoint treatment

    Include or exclude the start and end independently instead of relying on an unstated convention.

  3. 03Apply closures

    Choose the weekend pattern and either the observed U.S. federal holiday calendar or no holiday exclusions.

Observed holidays

For fixed-date federal holidays, Saturday normally observes Friday and Sunday normally observes Monday. Dynamic Monday/Thursday holidays are generated by rule.

What is not included

One-off executive closures, inauguration day, state/local holidays, courts, exchanges and employer-specific closures are outside this calendar.

Custom weekends

Saturday/Sunday is the default, with Friday/Saturday and Sunday-only patterns available for planning contexts that use them.

Rule trail

Rule set 2.0.0. Last reviewed 2026-08-22. Next review due 2027-02-22.

Questions answered

What to know before using the result.

How are business days counted?

CalcSpan applies your start/end inclusion choices, then excludes the selected weekend dates and, if enabled, dates in the current U.S. federal holiday pattern.

Does the business days calculator include federal holidays?

Yes by default, including normal Friday/Monday observance for fixed-date holidays. You can turn holiday exclusions off.

Does it include state holidays or company holidays?

No. State, local, court, exchange and employer calendars can differ and should be checked separately.

Can the start date count as business day one?

Yes. Turn on Include the start date. The date counts only if it is not a selected weekend or excluded holiday.