Date Difference Calculator
Pick two dates to see the exact time between them, updated as you type.
Pick an end date to see the difference.
Processed on your device — nothing is sent anywhere.
How it works
- Enter the start date in the first field.
- Enter the end date in the second field.
- Read the difference in days, years/months/days, weeks and business days.
Frequently asked questions
- Are both the start and end date counted?
- The calculator counts the number of full days between the two dates, so the start date itself is not included. For example, the difference between January 1 and January 2 is one day. If you need an inclusive count, add one to the result.
- How are business days calculated?
- Business days are all Mondays through Fridays that fall after the start date, up to and including the end date. Saturdays and Sundays are excluded. Public holidays are not excluded, because they vary by country and region.
- How does the years, months and days breakdown work?
- The breakdown uses calendar arithmetic: it advances whole years first, then whole months, then counts the remaining days. Because months have different lengths, the same total number of days can produce slightly different breakdowns depending on the dates involved.
- Does the calculator account for leap years?
- Yes. All results come from real calendar dates, so February 29 is included in leap years automatically and the day count across any range is exact. You never need to correct the result manually for leap years or for months of different lengths.
- Can I count down the days to a deadline or event?
- Yes — set the start date to today and the end date to the event, and the days figure is your countdown. For work deadlines the business days number is often the more useful one, since it excludes weekends and shows how many working days you actually have left.
About this tool
This date difference calculator measures the exact time between any two calendar dates. Pick a start and an end date and it reports the gap several ways at once: total days, a years-months-days breakdown, whole weeks plus remaining days, and business days with weekends excluded. The results update the moment you change either date.
All calculations use real calendar arithmetic performed in your browser — leap years and the varying lengths of months are handled by the date logic itself rather than by an approximation such as thirty-day months, so the answer matches what you would get by counting squares on a physical calendar. Nothing you enter leaves your device, no dates are logged or stored anywhere, and the page keeps working offline once it has loaded.
Common uses include working out how many days a project has left, checking notice periods and contract durations, counting business days for shipping or legal deadlines, measuring the gap between an invoice and its payment, and settling exactly how long ago something happened. The multiple formats spare you the conversion: a 100-day gap is shown in weeks and days, and as months plus a remainder, at the same time.
One habit avoids most off-by-one mistakes: decide up front whether your situation counts both endpoints. This calculator counts full days between the dates, excluding the start date — the natural reading of “how many days from A to B”. Deadlines phrased as “within 14 days including today” need one added to the comparison, as explained in the FAQ.