How to count days between dates
Agree on which days belong in the count. The arithmetic comes after that.
Free toolDate CalculatorCount days between dates, add or subtract time and skip days off. Turn your result into a shareable date card.Calculate your datesThe short answer
Subtract the earlier calendar date from the later one to find the elapsed day count. Count both dates for an inclusive period by adding one.
Working days need two more choices: which weekdays you work and which specific holidays or closures to skip. A date calculator can follow those rules, but it cannot decide them for you.
- Write the two dates with the month spelled out, or use an unambiguous date picker.
- Decide whether each endpoint belongs in the period.
- Choose calendar days or a defined working week.
- List any additional days off. Check the result against the calendar.
Why two correct answers can differ by one day
An elapsed span counts the gap between dates. An inclusive period counts the dates covered, including both ends.
From Monday 2 November to Monday 16 November 2026, 14 days pass. A booking that includes both Mondays covers 15 dates.
| Which endpoints count? | Calendar count | Dates counted |
|---|---|---|
| Start excluded, end included | 14 | 3 to 16 November |
| Start included, end excluded | 14 | 2 to 15 November |
| Both included | 15 | 2 to 16 November |
| Both excluded | 13 | 3 to 15 November |
The first two rows have the same calendar count but include different dates. That matters when a boundary lands on a weekend.
A weekend shows the difference
Friday 6 November to Monday 9 November 2026 spans three calendar days. Start included and end excluded gives one working day: Friday. Start excluded and end included also gives one: Monday.
Move the start to Saturday 7 November. Including Saturday and excluding Monday gives zero working days. Excluding Saturday and including Monday gives one. The rule must travel with the number.
Count working days without counting a holiday twice
Remove your weekly days off, then remove extra holidays that fall on remaining dates. A holiday already on a day off changes nothing.
| 2 to 16 November 2026, start excluded | Count |
|---|---|
| Calendar dates: 3 to 16 November | 14 |
| Saturday and Sunday dates | 4 |
| Working dates before extra exclusions | 10 |
| Manually exclude Wednesday 11 November | 9 working dates remain |
| Also exclude Saturday 7 November | Still 9. Saturday was already off. |
Here, 11 November is a deliberately entered example closure. The calculation does not assume a country, employer or public-holiday schedule.
A five-sevenths estimate can help with a rough plan. It fails on short intervals and special working weeks. Count complete weeks, then inspect the remaining dates.
Add days when the rule says days
Adding days moves through actual date boundaries. Adding months follows the calendar, which has unequal month lengths.
| Start and operation | Result | Reason |
|---|---|---|
| 31 Jan 2027 + 1 month | 28 Feb 2027 | February has no 31st. Use its last valid day. |
| 31 Jan 2027 + 30 days | 2 Mar 2027 | 30 date steps pass through all 28 days of February. |
| 31 Jan 2028 + 1 month | 29 Feb 2028 | The leap year has one more February date. |
| 2 Nov 2026 + 10 working days | 16 Nov 2026 | Start at day zero. Skip Saturdays and Sundays. No extra holidays. |
| 16 Nov 2026 − 10 working days | 2 Nov 2026 | Count eligible dates backwards. The starting Monday is day zero. |
For mixed units, floi applies years first, then months, then weeks and days. From 29 February 2024, adding one year and one month reaches 28 March 2025. Adding 13 months in one step reaches 29 March 2025. The intermediate clamp explains the difference.
Use Excel or Google Sheets when you have a list
A spreadsheet is useful for many rows of dates. Use real date cells and format the result as a number.
Put the earlier date in A2, the later date in B2 and extra excluded dates in H2:H10. These formulas assume A2 is on or before B2.
| Task | Formula |
|---|---|
| Elapsed calendar days | =B2-A2 |
| Both dates included | =B2-A2+1 |
| Working days, both dates included | =NETWORKDAYS.INTL(A2,B2,"0000011",H2:H10) |
| Working days, start excluded, end included | =IF(B2<=A2,0,NETWORKDAYS.INTL(A2+1,B2,"0000011",H2:H10)) |
| 10 working days after A2 | =WORKDAY.INTL(A2,10,"0000011",H2:H10) |
| One calendar month after A2 | =EDATE(A2,1) |
The seven-character week string starts on Monday. A 1 means a non-working day. So 0000011 takes Saturday and Sunday off, while 0000110 takes Friday and Saturday off.
Check the official references for Excel’s NETWORKDAYS.INTL, Google Sheets’ NETWORKDAYS.INTL and WORKDAY.INTL. Your spreadsheet locale may use semicolons as separators.
Check the tricky dates
Leap days, same-day ranges and calendar limits deserve a small explicit check. Multiplying years by 365 misses the actual dates.
| Date-only check | Expected result |
|---|---|
| 28 Feb to 1 Mar 2028 | 2 elapsed days. The leap date counts. |
| 28 Feb to 1 Mar 2100 | 1 elapsed day. The century is not divisible by 400. |
| The same date twice | 0 elapsed days. Both endpoints included gives 1 calendar day. |
| 7 to 9 Nov 2026, both excluded | 1 calendar day, Sunday. 0 Mon-to-Fri working days. |
| 8 to 9 Mar 2026 | 1 calendar day. A daylight-saving clock change does not change this count. |
Method and date: the synthetic examples on this page were checked on 2 November 2026 against the calculator’s date-only model. Executable checks in scripts/check-date-calculator.mjs compare the working-day formula with independent day-by-day enumeration. They also check leap centuries, endpoint combinations, date limits and calendar-file formatting.
Share the rule with the result
A useful date card carries enough context to understand its number. Keep the date range, snapshot date and exclusions visible.
- Use calendar days for a date-only countdown when every date matters.
- Use working days when the audience needs to understand an agreed schedule.
- Write the event name as a short title. Put the human message in the note.
- Review the saved image. A countdown image is a fixed snapshot, not a live page.
The date calculator makes eight card layouts in the browser. Use the social post maker for a fuller announcement, or the age calculator for birthdays and life milestones.
What this guide cannot decide for you
A calculator cannot settle court deadlines, contract interpretation, visa rules or payroll eligibility. Confirm the endpoints, applicable holidays and any special deadline adjustment with the organisation responsible.
For exact hours between instants, use a time-aware calculation with the appropriate timezones. This guide and floi’s date calculator count Gregorian calendar dates.