Duration calculator
Days Between Dates & Business Days
Count the calendar days between two dates, or switch on business days to exclude weekends and, optionally, US federal holidays.
How to use the days-between calculator
- Choose a start date and an end date. Order does not matter — the tool always reports a positive count.
- The headline number is the calendar days between them, with weeks and a years/months breakdown beside it.
- Tick Count business days only to drop Saturdays and Sundays.
- Tick Also exclude US federal holidays to remove observed federal holidays too; any that fall in your range are listed.
Calendar days vs business days
There are two honest ways to measure the gap between two dates, and they answer different questions.
Calendar days (elapsed). This is the headline figure: the number of days you would advance moving from the start date to the end date. It does not count the start date itself, so 1 January to 8 January is 7 days. This is the standard meaning of "days between two dates" and the basis for the weeks and years/months breakdowns.
Business days (working days). When you switch this on, the tool counts every weekday in the range and, unlike the elapsed figure, it includes both the start and end dates if they are weekdays. That matches the spreadsheet NETWORKDAYS function most offices rely on, which is why the business-day total and the calendar-day total are counted slightly differently. The business days vs calendar days guide works through the inclusive-versus-elapsed distinction with examples.
Excluding federal holidays uses observed dates. If a fixed-date holiday such as Independence Day lands on a Saturday, the federal government observes it on the preceding Friday; a Sunday holiday is observed on the following Monday. The built-in table covers all eleven US federal holidays for 2024 through 2030; ranges outside those years still exclude weekends but cannot subtract holidays, and the tool tells you when that happens.
As with every DateSpan tool, the counting is done on local year, month and day values — never a UTC timestamp — so a date entered as the 1st is always treated as the 1st, whatever your time zone or the hour of day.
Frequently asked questions
How do you count the number of days between two dates?
Subtract the earlier date from the later one. The headline number is elapsed days — from the start date up to the end date, not counting the start date itself. So 1 January to 8 January is 7 days.
What counts as a business day?
Any weekday, Monday through Friday. Turn on the business-days option to exclude Saturdays and Sundays, and optionally US federal holidays too.
Does the business-day count include the start and end dates?
Yes. The working-day total counts both endpoints when they are weekdays, matching a spreadsheet NETWORKDAYS formula. That is why it can differ from the elapsed calendar-day figure.
Which holidays are excluded?
The eleven US federal holidays, on their observed dates (a Saturday holiday shifts to the preceding Friday, a Sunday holiday to the following Monday). The holiday table covers 2024 through 2030.
Why does another site show a different number?
Usually it is counting inclusively rather than elapsed days, or a timezone conversion shifted a date by one. This tool uses local date components only, so it does not drift.
DateSpan is a free calendar utility. Holiday data reflects US federal holidays 2024–2030 and may not match your employer's, school's, or another country's holiday schedule. Results are calendar arithmetic for general informational purposes only, not legal or payroll advice.