Date Duration & Business Days Calculator
Count the days between two dates, add or subtract days from a date, or count working days only. Skip weekends, public holidays for the US, UK, Canada or Australia, and any dates of your own, and see the weeks, months and the next working day.
Written by Suhaib Hassan. Holiday lists follow the official rules for each country. Our methodology.
It counts whole days between dates, then removes weekends and holidays one date at a time to get working days.
Deadlines, notice periods and delivery times often run in business days. This shows both counts side by side.
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Dates from today
Common offsets from today, with the weekday each lands on.
Quarter and fiscal-year working days
Calendar and working days for each quarter of the current year and the US federal fiscal year, using your holiday choice and weekend setting above.
| Period | Start | End | Calendar days | Working days | Holidays on weekdays |
|---|
How the counts work
Calendar days
days = (end − start) ÷ 86,400,000 ms (+1 if the end day is included)Working days
count each date d in [start, end) where d is not a weekend, holiday or extra day offLeap year
(y mod 4 = 0 and y mod 100 ≠ 0) or y mod 400 = 0What is skipped
US federal holidays are the eleven in 5 U.S.C. 6103. A holiday that falls on a Saturday is observed on Friday and one on a Sunday on Monday. UK, Canada and Australia lists cover the common national holidays, and moving rules such as Easter are calculated.
Regional and one-off holidays are not included. Add them in the extra days off box.
Worked examples
Illustrative dates, each checked by hand.
9 Mar to 1 Jun 2026
Calendar days between the dates.
April 30 + May 31 = 61
+ 1 day into June = 84 days
= 12 weeks exactly
Working days in that range
US federal holidays, weekends skipped.
− Memorial Day (25 May) = 59 working days
Add 90 days
To 9 March 2026.
+ 30 → 30 Apr, + 31 → 31 May
+ 7 → 7 Jun 2026, a Sunday
How to count days between two dates
- Pick the start and end dates and decide whether the end day counts.
- For calendar days, subtract the dates. Leap days are handled automatically.
- For business days, remove weekends and any public holidays that fall on weekdays.
- To find a deadline, use Add or subtract days with the business-day option.
Contracts and laws define how days are counted. Check whether the first or last day is included, and which holidays apply, before relying on a date.
By Suhaib Hassan · Reviewed 29 September 2026 · How CalculatePilot verifies formulas →
Sources
- 5 U.S.C. § 6103, Holidays, and U.S. Office of Personnel Management, Federal Holidays.
- GOV.UK, UK bank holidays.
- Government of Canada, Statutory holidays (federal).
- ISO 8601, Date and time — Representations for information interchange.
Frequently asked questions
Is the end date included in the count?
By default no: the count runs from the start date up to, but not including, the end date. Turn on Include the end day to add one. Legal deadlines often specify the rule, so check yours.
How are business days counted?
Every date in the range that is not a Saturday, Sunday, chosen public holiday or extra day off counts as a working day. A holiday that falls on a weekend is not deducted twice.
Which US holidays are skipped?
The eleven federal holidays: New Year's Day, Martin Luther King Jr. Day, Washington's Birthday, Memorial Day, Juneteenth, Independence Day, Labor Day, Columbus Day, Veterans Day, Thanksgiving and Christmas Day, with weekend observance rules.
How does the tool handle leap years?
Dates are counted on the real Gregorian calendar, so 29 February is included in leap years. A year is a leap year if divisible by 4, except centuries not divisible by 400.
Why is the next working day useful?
It shows when work resumes after the interval ends, skipping weekends and holidays. It is handy for delivery windows, notice periods and project handovers.
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