Loading tool workspace...
Find the number of days, weeks, months, and years between two dates in your browser, in either order.
See the calendar difference plus total days and weeks, with leftover days shown.
If the end date is earlier, the result says "X days before" instead of silently swapping the dates.
Dates are calendar days, so a 23-hour or 25-hour day never changes the count.
February in leap years and month-end dates are handled with documented rules.
When you use Date Difference Calculator, your data never leaves your browser. All transformations execute in-memory on your local machine with zero server uploads. Web assets are downloaded to run the tool, but your input data is never transmitted.
No. The calculation runs in your browser. The page does download the code needed to run the tool.
No. It counts the days from the start date to the end date, so the same date twice is 0 days and a date and the next day is 1.
The dates are not swapped for you. The gap is shown as a positive size with the direction written out, for example "The end date is 30 days before the start date."
Whole months are added to the start date (using the last day of a shorter month when needed), and the remaining days are shown separately.
The dates can be in either order: the result says whether the end date comes before or after the start date, and nothing is swapped for you. Years, months and days are calendar differences (whole months first, then the remaining days). Dates are read as calendar dates, so daylight-saving changes and time zones never add or remove a day. Processed locally in your browser.