Counting the Days Between Two Dates
Counting days by hand is surprisingly error-prone: months have 28, 29, 30 or 31 days, leap years add an extra day every four years (with exceptions), and it is easy to forget whether the first and last days should both be counted. This calculator handles all of that automatically and shows the gap in several useful forms at once.
Should the end date be included?
By default, the calculator gives the standard difference — the number of midnights between the two dates. From Monday to Friday is 4 days. Choose "include end date" when you are counting days that are each occupied, such as the length of a hotel stay including check-out day, the duration of an event, or a contract that runs "from the 1st to the 10th inclusive" (10 days).
Business days
Business days count Monday to Friday only. They are commonly used for delivery estimates, payment terms, legal notice periods and project planning. Public holidays vary by country, region and even company, so they are not removed automatically — subtract any holidays that fall within your range for an exact count.
Leap years explained
The Gregorian calendar adds February 29 in every year divisible by 4, except for century years that are not divisible by 400. So 2000 and 2024 were leap years, while 1900 was not and 2100 will not be. Over a 400-year cycle this produces an average year of 365.2425 days — very close to the solar year.
| Unit | Days |
|---|---|
| Common year | 365 |
| Leap year | 366 |
| Average Gregorian month | ≈ 30.44 |
| Business days in a typical year | ≈ 260–262 (before holidays) |
Popular uses
- Counting down to a holiday, wedding, exam or retirement date.
- Checking how long ago an event happened.
- Working out notice periods, warranty windows and payment due dates.
- Planning projects in working days.
- Tracking a streak or habit — for example, days since you quit smoking.
Need to find a date instead of a difference? Use the add or subtract days calculator. To count your own life in days, try our age in days calculator.
Frequently Asked Questions
How many days are there between two dates?
Choose the two dates above. The calculator counts the exact number of days, accounting for different month lengths and leap years.
Does it count the start date?
The standard difference counts the days from the start date up to, but not including, the end date. Select the 'include end date' option to count both days.
Are public holidays excluded from business days?
No — holidays differ by country and organisation, so only Saturdays and Sundays are excluded. Subtract any holidays in the period manually.
Can I calculate dates in the past?
Yes. The calculator works for any two dates, in any order. If the end date is before the start date, the result is shown with a minus sign.
Disclaimer: Calculations use the Gregorian calendar and your device's local time zone. Results are provided as-is for informational purposes.
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