Days between two dates calculator

How days between two dates are counted

The calculation uses calendar dates: each date becomes a day number and the two numbers are subtracted. Daylight saving changes cannot add or remove a day, and leap days land in the right place.

\[ \text{days} = \text{end day number} - \text{start day number} \ (+ 1 \, \text{if the end date is included}) \]

Without the end date, January 1 to January 2 is 1 day. With the end date included it is 2 days, which is how you count a hotel stay, a rental or a notice period that includes both ends.

Years, months and days: the end-of-month rule

For the years-months-days breakdown, whole months are added to the start date until the next step would pass the end date. If the day does not exist in the target month, the last day of that month is used.

Weekdays versus business days

The tool also counts Monday through Friday. That is not quite the number of business days, because U.S. federal holidays are not removed here. For contract deadlines, shipping estimates or payroll, use the business days calculator, which skips holidays.

Days between dates: method and examples

To count the days between two dates, work in steps. First, note the start and end dates. Then decide whether to include the end date. Finally, read the total in days, weeks, hours and months.

For example, from October 30 to December 25, 2026 you count 56 days: 31 days to November 30, then 25 days in December. That is exactly 8 weeks. If you include the end date, the total becomes 57. So the option changes the answer by one, and that one day can matter for a lease or a contract.

Days between dates: common uses

This calculation shows up in daily life. Here are the most common uses.

• Leases and notices: the exact length of a stay or a period.
• Pregnancy: the number of days since a key date.
• Travel: trip length, nights included.
• Projects: time left before a delivery.
• Fitness: training days before a race.

However, for a hotel stay, count nights rather than days. From August 10 to August 17, you spend 7 nights but are present on 8 calendar days. If you want to skip weekends, switch to the business days calculator.

Days between dates: mistakes to avoid

Most mistakes come from the end date. First, people forget to include it when the contract requires it. Second, they count months as 30 days, though some have 31 or 28. Third, they ignore February 29 in leap years.

So let the tool do the math, then compare with another view. For example, to learn someone's age, the age calculator returns years, months and days. To move forward from a date, open the tool to add days to a date.

Days between dates: quick benchmarks to remember

Here are handy benchmarks. So you can sanity check a result fast. For example, a week has 7 days, a quarter about 91 days and half a year about 182 days. Also, from January 1 to July 1 of a common year, there are 181 days. In fact, January through June total 31, 28, 31, 30, 31 and 30 days.

If you also want hours, multiply days by 24. For example, 56 days equal 1,344 hours. Finally, to convert to weeks, divide by 7.