Calculate days between dates →
The basic rule
Subtract the earlier date from the later one. From 1 March to 15 March is 14 days. If you want to count both the first and the last day, add one, which gives 15.
Across months and years
Months have different lengths, which makes counting by hand easy to get wrong. Leap years add a day on 29 February. A calculator handles both and also shows the gap in weeks, months and years.
Working days
- Count the full weeks in the range and multiply by 5.
- Add the weekdays left over in the partial week.
- Subtract public holidays that fall on weekdays.
Common uses
- Notice periods and contract deadlines.
- Countdowns to holidays, due dates and events.
- Counting how many days a project or trip lasts.
Try it
Use Days Between Dates for the gap between two dates, or the Date Calculator to add or subtract days from one date, for example what date is 90 days from today.
Examples
From 1 January to 31 December in a normal year is 364 days, or 365 if you count both ends. From 15 June to 15 September is 92 days. A 90-day deadline that starts on 1 November ends on 30 January. Use the date calculator to check any deadline instead of counting on a calendar.
Mistakes to avoid
- Forgetting that February has 28 or 29 days.
- Not agreeing whether the first day counts.
- Treating a month as always 30 days.
- Forgetting public holidays when you count working days.