Date Difference Calculator
Enter a start and end date to see exactly how far apart they are.
How the difference is calculated
This calculator counts full calendar years, months, and days between two dates, the same way you'd count by hand on a calendar — not by dividing total days by average month lengths, which can produce misleading results. It also shows the raw total days and weeks between the dates for a quick, unambiguous figure.
If the end date is earlier than the start date, the dates are swapped internally so the difference is always shown as a positive value.
Frequently asked questions
Why don't years × 365 days match the total days shown?
Leap years add an extra day roughly every 4 years, so a date range that spans one or more leap years will have slightly more total days than a simple 365-day estimate would suggest.
Does the order of start and end date matter?
No — you can enter the dates in either order. If the end date comes before the start date, the calculator automatically treats it as a swapped range and still returns a positive difference.