Date Calculator

Find the exact duration between two dates, or add/subtract days from any date.

Start Date
End Date

Select two dates and click Calculate.

Frequently Asked Questions

The calculator counts the exact number of calendar days between the two dates, including leap year days. The result is also broken down into total weeks, months (approximate), and years (approximate) for easy reading. Weekdays and weekends are counted separately for workday planning.
Yes, all calendar days are counted by default. The tool also shows how many of those days are weekdays (Mon–Fri) and how many are weekends (Sat–Sun). Public holidays are not excluded since they vary by country and region.
Yes. In the "Add / Subtract Days" tab, choose "Subtract" and enter the number of days to go back in time from your chosen start date. There is no limit on how far back or forward you can calculate.
Calendar months count complete months between two dates (e.g., Jan 1 to Mar 1 = 2 months exactly). Approximate months divide total days by 30.44 (the average days per month). This tool shows the approximate value alongside the exact day count so you always have both references.
This calculator counts the number of days between the start and end dates, meaning the start date is counted but the end date is not (exclusive end). For example, from January 1 to January 5 = 4 days. This is the standard mathematical difference and is used in financial contracts. If you need to count both endpoints (inclusive), add 1 to the result.
Leap years are handled automatically. A leap year occurs every 4 years (e.g., 2024, 2028), except century years not divisible by 400 (e.g., 1900 was not a leap year, but 2000 was). The calculator uses JavaScript's native Date object, which correctly accounts for February 29 in leap years, so all date arithmetic is precise.
Yes. The date difference result shows a breakdown of weekdays (Mon–Fri) and weekends (Sat–Sun) separately. You can read the weekday count directly to find the number of working days between two dates. Note that public holidays are not excluded since they vary by country and region.
The result table shows the total days, then converts to weeks (days ÷ 7), months (days ÷ 30.44), and years (days ÷ 365.25). These are approximate conversions. For precise calendar months (e.g., "exactly 3 months and 5 days"), you would need to count forward month-by-month.
Enter the person's date of birth as the Start Date and today's date as the End Date, then click Calculate. The result in years (approximate) gives their age. Use the "Set End = Today" button for convenience. For legal or official purposes, age is typically counted in completed years — which matches the approximate years shown in the result.
No. This calculator works with calendar dates only, treating each date as midnight in local time. Time zones are not relevant for calculating the number of days between two calendar dates. For date-only calculations (project deadlines, tenures, durations), time zones have no effect.

About This Date Calculator

This free date calculator finds the exact number of days, weeks, months, and years between any two dates, or adds and subtracts a duration from a start date to find a target date. All calculations happen instantly in your browser.

Useful for contract deadlines, project planning, age differences, and any scenario where you need precise elapsed-time or future-date arithmetic.

When to use this calculator

  • Counting days between contract signing and deadline
  • Finding the date N days from today
  • Calculating exact age difference between two birthdays
  • Determining how many days until an event
  • HR — employee tenure, notice periods

Standards & References

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