Business days calculator
This business days calculator counts business days between two dates or adds business days to a date. The math runs in your browser; nothing is sent anywhere.
Last verified: October 16, 2026Sources & methodologyFound an error? Tell us
How it counts
- A business day is Monday to Friday, minus the observed holidays of the calendar you pick.
- Counting between two dates includes both dates. If the end is before the start, the count is negative.
- Adding N business days does not count the start date; adding 0 returns the same date.
- The data covers 2026–2027. For other years, or to use this math in an app, use the API.
Example: 10 business days after is on the federal calendar, but for banks, because the Federal Reserve does not move Saturday holidays.
This calculator is for quick lookups. Apps should use the OpenDay API (business-days/add and business-days/between), which covers 2000–2100 and returns the source with every answer.
More
Frequently asked questions
How many business days are between two dates?
Pick a calendar and both dates in "Business days between two dates". Both dates are counted, and weekends and observed holidays are excluded.
What date is 10 business days from today?
The "Add or subtract business days" tool starts from today: enter 10 (or 5, or 30) and pick your calendar. The start date itself is not counted.
Can it count bank business days?
Yes. Pick "US – banks (Federal Reserve)": it skips Federal Reserve holidays, which do not move Saturday holidays to Friday, so the result can differ from the federal calendar.