About this day counter
Counting days by hand on a calendar is slow and easy to get wrong, especially across months of different lengths and leap years. This calculator counts the exact number of days between two dates and shows the same span in several useful ways: years, months, and days for ages and contracts, weeks for pregnancies and projects, business days from Monday to Friday for deadlines and delivery times, and hours, minutes, and seconds. By default the end date is not counted, which matches how most people count the time until an event; tick the option to count both days.
How to count the days between dates
- Choose the dates. Pick a Start date and an End date, or press a quick range such as Next 90 days.
- Decide about the end date. Tick Include the end date when both days should count, for example for a hotel stay counted in days rather than nights.
- Press Count days. The totals appear, with the span shown on a timeline and details about each date.
Frequently asked questions
Is the end date included?
Not by default. From 1 January to 10 January is 9 days, the same as the number of nights between them. Tick Include the end date to count both days, which gives 10.
How are business days counted?
Every Monday to Friday in the span counts as a business day, and Saturdays and Sundays count as weekend days. Public holidays are not removed, because they differ by country.
How are years, months, and days worked out?
Whole months are added to the start date first, then the remaining days are counted. From 31 January, one month later is the last day of February, so 31 January to 1 March is 1 month and 1 day.
Are leap years handled?
Yes. Every 29 February in the span is counted, and the tool tells you how many leap days are included. Years divisible by 100 are leap years only when they are also divisible by 400.
What if the end date is before the start date?
The dates are swapped and the result is the number of days between them, so you never get a negative count. A note above the results tells you when this happened.