Date Calculator

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

Duration Result

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 (loan day counts, lease periods). 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 — including multi-year spans crossing multiple leap years — 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 — you will need to manually subtract any public holidays that fall within the period.

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 — this is useful for contract durations but less common for general calculations.

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. The total days and weeks are also shown. 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. If you are calculating the exact hours and minutes elapsed across time zones, you would need a dedicated time zone converter. 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. Enter two dates to get the difference, or enter a date plus a number of days to find the result — 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 without relying on a calendar app.

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

Standards & References

About Date Calculator

What This Tool Does

The Date Calculator helps you find the exact duration between two dates — in days, weeks, months, and years. You can also calculate a future or past date by adding or subtracting a number of days from any start date. All calculations are done instantly in your browser.

Common Use Cases
  • Project deadlines — days until due date
  • Contract duration — start to end date
  • Event planning — days until a birthday or anniversary
  • Finance — loan term or investment period
  • HR — employee tenure, notice periods

Related Calculators

Age Calculator
Due Date Calculator
Period Calculator
Time Converter

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