About the Date Difference Calculator
Find out exactly how much time separates two dates, broken down into total days, weeks, months and years, plus a business-day count that excludes weekends (or any weekdays you choose). Optional time-of-day inputs let you get precise hour, minute and second totals too.
How to use it
- 01Enter a start date (and optional time).
- 02Enter an end date (and optional time).
- 03Optionally tick weekdays to exclude from the business-day count.
- 04Read the breakdown: total days, weeks+days, years/months/days, and totals in hours/minutes/seconds.
Features
- Calendar-accurate years/months/days breakdown, not just a raw day count divided evenly
- Business-day count with a configurable set of excluded weekdays
- Total hours, minutes and seconds for precise scheduling needs
- Clearly flags and handles the case where the end date is earlier than the start date
Practical examples
Project deadlines
Find out how many business days remain until a deadline, excluding weekends.
Age calculation
Enter a birth date and today's date to get an exact age in years, months and days.
Contract terms
Calculate the exact duration of a contract period including hours if start/end times matter.
Limitations
- Business-day counting excludes selected weekdays only; it does not account for public holidays.
- Time inputs are treated in your browser's local time zone; there is no cross-time-zone adjustment here (use the Time Zone Converter for that).
Privacy
All date math happens locally in your browser using JavaScript's Date object. No dates are sent anywhere.
Read the full privacy policy for how the site as a whole handles data.
Frequently asked questions
What happens if the end date is before the start date?
The tool detects this, shows a warning, and reports the absolute difference between the two dates.
Does the business-day count include holidays?
No, only weekday exclusion is supported; holidays are not built in since they vary by country and region.
Why do years/months/days differ from dividing total days by 365?
Calendar months have different lengths, so a true calendar breakdown accounts for that instead of using an average.