Counting the number of days between two dates is one of the most common calendar tasks — for deadlines, trips, age, or billing. Doing it by hand is fiddly because months vary in length and leap years add a day. Here's how to get it right.
For an instant, accurate answer between any two dates, use the date calculator.
The simple method
To count days between a start date and an end date:
- Count the remaining days in the start month.
- Add the full days in every whole month in between.
- Add the days in the final month up to the end date.
- Account for any 29 February in a leap year within the range.
This works, but it's error-prone across long spans — which is exactly what the date calculator is for.
Inclusive vs exclusive counting
A crucial detail: do you count both end dates, or just one?
- Exclusive (the usual "difference"): from 1 March to 3 March = 2 days (the gap between them).
- Inclusive (counting both days): from 1 March to 3 March = 3 days (1st, 2nd, and 3rd).
For durations like "how long until…", use the exclusive difference. For things like "how many days is this event running," use inclusive counting (add 1).
Don't forget leap years
If the range includes a 29 February, add that extra day. 2026 is not a leap year, but 2028 is — so a span crossing Feb 2028 gains a day. See is 2026 a leap year?
Counting working days only
If you only want working days (Monday–Friday, excluding weekends and holidays):
- Count the total days in the range.
- Subtract the weekends.
- Subtract public holidays that fall on weekdays.
The date calculator can count working days directly, and the long-weekend planner helps you spot holiday gaps.
Quick answers
How do I count days between two dates? Count the days left in the first month, add whole months between, add days in the final month, and include any 29 February — or use the date calculator.
What's the difference between inclusive and exclusive counting? Exclusive counts the gap between dates; inclusive counts both end dates (add 1).
How do I count only working days? Take the total days, subtract weekends, then subtract any weekday public holidays.
Do leap years affect the count? Yes — if the range includes 29 February, add that extra day.