How to count the days between two dates
Enter a start date and an end date. By default the calculator gives the difference between them, which is what you need for "how many days until" or "how many days since" questions. Tick Include the end date when both the first and last day count, for example when counting the days of a holiday, a hospital stay or a work assignment.
Days between = end date − start date
Days including both = end date − start date + 1
Worked example: from 1 March 2026 to 25 December 2026 there are 299 days. That's 42 weeks and 5 days, or 9 months and 24 days. 214 of those days are weekdays. If you include 25 December itself, the count is 300 days.
Days in each month
| Month | Days | Month | Days |
|---|---|---|---|
| January | 31 | July | 31 |
| February | 28 (29 in leap years) | August | 31 |
| March | 31 | September | 30 |
| April | 30 | October | 31 |
| May | 31 | November | 30 |
| June | 30 | December | 31 |
A common year has 365 days and a leap year has 366. A year is a leap year if it divides by 4, except century years, which must divide by 400. So 2000 was a leap year, 2100 won't be, and 2028 will be.
Why "months between" is less exact than days
Because months have different lengths, "3 months" can mean anywhere from 89 to 92 days. The calculator counts whole calendar months first (15 January to 15 April is 3 months), then the remaining days. When a contract or law sets a period in days, use the day count; when it sets it in months, use the months.
Common uses
- Travel and visas: count the days of a stay. Many visa rules count both the arrival and departure days, so include the end date.
- Projects and school terms: see how many weekdays are left until a deadline.
- Anniversaries and milestones: find out when you'll reach 1,000 or 10,000 days together, or since an event.
Frequently asked questions
How many days are between two dates?
Subtract the earlier date from the later one. The calculator above does it instantly and accounts for months of different lengths and leap years. Add one day if you want to count both the start and end dates.
Should I include the end date?
It depends on what you're counting. For "how many days until" or the length of a loan, don't include it. For the number of days of an event, a stay or a rental where both the first and last day are used, include it.
How many weekdays are between two dates?
The calculator shows the number of Monday-to-Friday days in the range. To also skip public holidays, use the business days calculator, where you can list holiday dates.
How many days are in a year?
365 in a common year and 366 in a leap year. On average, a Gregorian year is 365.2425 days long.
Days are counted on the Gregorian calendar. Legal and contractual periods sometimes follow special rules, such as excluding the first day or moving a deadline that falls on a weekend.