How to use the date calculator
- Pick what you need. Choose Days between, Add or subtract, or Countdown.
- Enter your dates. Pick a start and end date, or a start date and a number of days, or the date you are counting down to.
- Choose your options. Include the end date if you are counting both days, or count only weekdays for working days.
- Read the result. See the total in days, weeks and days, months and days, plus working days and the weekday of the result.
The formula and worked examples
Days between two dates = end date − start date. That count does not include the end date, which is how most calendars, contracts and spreadsheets count. Tick "Include the end date" to count both days, for example for hotel nights you pay for or a holiday you are away for.
Example 1: from Sunday 15 March 2026 to Saturday 4 July 2026 is 111 days, which is 15 weeks and 6 days. Of those, 80 are working days (Monday to Friday). Counting both dates gives 112 days.
Example 2: 90 days after Monday 19 October 2026 is Sunday 17 January 2027. Counting 10 working days instead lands on Monday 2 November 2026.
Quick reference: key dates in late 2026
| Date | Day | What |
|---|---|---|
| 25 October 2026 | Sunday | Clocks go back in the UK and most of Europe |
| 31 October 2026 | Saturday | Halloween |
| 1 November 2026 | Sunday | Clocks go back in the US and Canada |
| 26 November 2026 | Thursday | Thanksgiving (US) |
| 31 December 2026 | Thursday | Last day of 2026 (2026 has 365 days) |
| 1 January 2027 | Friday | New Year's Day |
Days in each month
January, March, May, July, August, October and December have 31 days. April, June, September and November have 30. February has 28 days, or 29 in a leap year. 2026 and 2027 are not leap years; 2028 is.
Counting days in Excel or Google Sheets
Put the start date in A1 and the end date in B1. =B1-A1 gives the days between them, and =DATEDIF(A1,B1,"d") does the same. =NETWORKDAYS(A1,B1) counts working days, including both the start and end date, and =WORKDAY(A1,10) adds 10 working days.
Need an exact age instead? Use the age calculator. Working out hours between two times or a timesheet? Try the time calculator.
