Time & Date · Date Math
Working Days Calculator
Count the working (business) days between two dates, skipping weekends and the public or company holidays you list — with the option to include the end date, and any weekend pattern.
A ready-made version of the Date Difference Calculator.
How this is calculated
Years, months, days: step whole months from the earlier date (clamping to month ends), then count the remaining days
- Working days
- Days from the start (inclusive) to the end (exclusive) that aren't weekend days or listed holidays; negative if the end is earlier
- Include end date
- Adds one day so both the start and end dates count
The years-months-days answer walks the calendar month by month from the earlier date, so it reflects real month lengths rather than a 30-day average — 31 January to 29 February 2024 is exactly 1 month. Total days count the gap between the dates (1 to 3 March is 2 days); switch on 'include the end date' to count both ends. If the end date is before the start date, every figure is shown as negative.
Assumptions & sources
- Dates are whole calendar days in one time zone; hours and minutes are whole days × 24 × 60.
- Working days use your weekend setting (Saturday–Sunday by default) and the holidays you list.
- 1ISO 8601 — Date and time format (week numbering, calendar dates) — International Organization for Standardization
- 2Calendrical Calculations (Reingold & Dershowitz) — Cambridge University Press
Calculator ID TIME-DATEDIFF-001/workdays · version 2.0.0
Common questions
Does this match Excel's NETWORKDAYS?
Yes, with 'Count both the start and end dates' on (the default here) and a Saturday–Sunday weekend: NETWORKDAYS counts both ends.
Can I exclude public holidays?
Yes — list them in the holidays table (you can paste a column of dates). Holidays falling on a weekend are ignored, as they don't remove a working day.