Date Difference Calculator
Formula
Days = |End Date − Start Date|
This calculator finds the exact number of days between any two dates. It accounts for leap years and varying month lengths. The result is always positive regardless of date order.
How to use
- Set the Start Month, Start Day, and Start Year.
- Set the End Month, End Day, and End Year.
- Read the result in Days, Weeks, and Months.
- Order doesn't matter; the result is always positive.
Example
From January 1, 2026 to December 31, 2026 is 364 days, or about 52 weeks and 12 months. The result counts every calendar day between the two dates.
Frequently Asked Questions
Does this account for leap years?
Yes. The calculation uses actual calendar dates, so February 29 is correctly handled in leap years.
Does the order of dates matter?
No. The result is always the absolute difference — you'll get the same answer whether you put the earlier or later date first.
How many days in a year?
365 days in a regular year, 366 in a leap year. The average is 365.25 days.
How accurate is the months calculation?
The months output is approximate — it divides total days by 30.44 (average days per month). For exact month counts, consider the specific months involved.
Does the result count both the start and end dates?
The calculator returns the gap between the two dates, not an inclusive count of every calendar day touched. For example, from June 1 to June 3 it reports 2 days, because that's the span between them. If you need to count both endpoints (such as the total number of days in a hotel stay or a project), add 1 to the result.
Can I use this to count working days or business days?
No, this tool counts all calendar days, including weekends and public holidays. For business-day calculations you'd typically subtract weekends (roughly two days per week) and any holidays that fall in the range. As a rough estimate, a 30-day calendar span usually contains about 21 to 22 weekdays.