Date Difference Calculator
Calculate the exact duration between two dates in several useful formats.
Enter a start date to compare the two dates.
The end date defaults to today and can be changed.
About the Date Difference Calculator
The Date Difference Calculator measures the calendar duration from a start date to an end date. It reports one result as years, months and days while also showing totals in other practical formats.
Exclusive counting measures elapsed time up to, but not including, the end date. Inclusive counting includes both boundary dates, which is useful for trips, events, bookings and records where every listed date counts.
Calendar months do not have a fixed number of days. This calculator counts completed calendar months first, then reports the remaining days, correctly accounting for February, leap years and month-end dates.
All calculations use date-only UTC arithmetic. Local time zones and daylight-saving clock changes cannot shift the result by a day, and the dates stay in the browser.
Key features
- Exact years, months and days
- Total days and weeks plus days
- Calendar months plus remaining days
- Inclusive and exclusive counting modes
How to use
- 1Enter the earlier date as the Start date.
- 2Keep today's date or choose another End date.
- 3Choose Exclusive or Inclusive counting, then review every duration format.
Frequently asked questions
- What is the difference between exclusive and inclusive counting?
- Exclusive counting omits the end date. Inclusive counting includes both the start and end dates, so its total is one day greater for the same date range.
- Does the calculator handle leap years?
- Yes. Total days and calendar duration account for February 29 in leap years and February's shorter length in other years.
- Why are months shown with extra days?
- Months vary from 28 to 31 days. The calculator counts complete calendar months from the start date, then shows the days left after the last complete month.
- What happens if the start date is after the end date?
- The calculator displays a validation message. Enter the earlier date first so the direction of the duration is clear.
- Are daylight-saving changes included?
- No clock adjustment is needed because this tool compares calendar dates rather than local times. Each elapsed calendar day counts as one day.