Plan a working schedule
Count available workdays, then verify the full calendar span.
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Business Days Calculator with Holiday Dates
Calculate working days in an inclusive date range using selected workweek days and optional user-supplied holiday dates.
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Holiday dates
How this calculator works
Count working days across an inclusive date range. Choose whether Saturdays and Sundays are part of the workweek and optionally supply holiday dates. CalcOS does not infer a country or regional holiday calendar.
- Method
- Inclusive proleptic Gregorian calendar-day enumeration with explicit workweek and supplied-date exclusions
- Source
- CalcOS Business Days Holiday-Date Correction Contract v1.0.0
- Last reviewed
- 2026-08-21
Method limitations
- No automatic country or regional holiday calendar
- Only Saturday and Sunday can be toggled as recurring non-working weekdays
- Ranges are limited to 36,525 inclusive calendar days
Engine-backed example
Business days between two dates: worked example
How many business days are there from August 3 to August 14, 2026, excluding weekends and August 7 as a holiday?
- Date range
- August 3–14, 2026 (inclusive)
- Weekend rule
- Exclude Saturdays and Sundays
- Holiday date
- August 7, 2026
Business / Working Days9 Days
- Total Calendar Days
- 12
- Workweek Days Excluded
- 2
- Eligible Holidays Excluded
- 1
The 12-day inclusive range contains two weekend days and one eligible weekday holiday, leaving 9 business days.
Trust and review
Who created and reviewed this calculator?
- Author
- CalcOS Editorial TeamResponsible for calculator explanations, examples, assumptions, and search-intent clarity.
- Reviewed by
- CalcOS Scientific ReviewTechnical review of integer calendar arithmetic, UTC date handling, boundaries, holiday-date classification, engine parity, and narrative examples.
- Substantive review date
- 2026-08-21Formula behavior, units, inclusive date boundaries, weekend toggles, holiday validation, worked-example parity, and stated limitations.
Sources
- CalcOS Business Days Holiday-Date Correction Contract v1.0.0
- ECMA-262 Date Time String Format
Assumptions used by this calculator
- The date range is inclusive and reversed dates are normalized.
- Saturday and Sunday exclusions follow the user-selected toggles.
- Only unique, valid, in-range holiday dates on otherwise working days are deducted.
- No country or regional holiday calendar is inferred.
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