Business days calculator: count business days between dates

How to use the business days calculator

The page has one form with three modes.

1. Under Calculation, choose Count between dates, Add business days or Subtract business days.
2. Count between dates asks for a Start date and an End date. Add and Subtract ask for a Start date and a Number of business days.
3. Choose whether to count the endpoints with Include start date and, in Count between dates, Include end date. By default, count mode excludes the start and includes the end, so Monday to Friday of one week gives 4 business days.
4. Under Working weekdays, select which weekdays count as work. Monday to Friday is checked by default; any combination, including Saturday or Sunday, works.
5. List Holiday dates to exclude, one per line, or separated by commas or spaces. A starting example, 2026-09-18, is filled in.
6. Select Calculate. Read the result and the breakdown, then select Copy report or Download text.

Reset restores the starting example dates, weekdays and holiday.

How business days are counted

In Count between dates, a calendar day counts as a business day when its weekday is selected and it is not one of your entered holiday dates. Reversing the start and end dates gives a negative count; the breakdown always shows the magnitude. A start date equal to the end date counts once only when both endpoints are included and that date is a business day.

In Add or Subtract business days, the start date is excluded unless you include it, and it then counts only if it is itself a business day. A positive number of business days lands on the last counted business day. Requesting zero business days returns the unchanged start date, even when that date is a holiday or not a working weekday.

Only the exact holiday dates you enter are excluded, and only when they fall on a selected working weekday. A holiday date outside the range, or on an unselected weekday, is not subtracted, because it was never counted.

Worked example

The starting example counts business days from September 14 to September 21, 2026, excluding the start and including the end, with Monday to Friday as working weekdays and September 18 entered as a holiday.

That range holds 7 calendar days. Two of them, Saturday the 19th and Sunday the 20th, fall outside the selected weekdays. September 18 is a Friday and a selected weekday, so it is excluded as the one holiday. The result is 4 business days, and the breakdown lists 7 calendar days considered, 2 non-working weekdays and 1 holiday excluded on a working weekday.

Change the mode to Add or Subtract business days to find a date instead of a count. Adding 5 business days to September 14, 2026 with the same weekdays and no holiday lands on September 21, 2026, a Monday; adding the same holiday moves the result to September 22.

Limits

This calculator has no bundled public, statutory or observed-holiday calendar for any country or region. It only excludes the exact holiday dates you type in, so a real deadline calculation needs your own accurate holiday list, including any observed-date shift.

It has no time-of-day field. Business days are whole calendar days in the proleptic Gregorian calendar, counted with UTC date arithmetic, so daylight-saving changes never add or remove a day. This is not an elapsed-clock-time duration calculator, and it does not model historical calendar transitions.

The supported date range is 0001-01-01 to 275760-09-13, the positive-year part of the browser's native date range; a start date, an end date or a requested result date outside that range gives an error. Add and Subtract need at least one selected working weekday when the requested number of business days is greater than zero.