Date Difference Calculator — Days, Months, Years

Dates

Start date

End date

Include both start and end dates Weekdays only (Mon–Fri) Auto swap if start > end

Or press Enter in an input

Summary

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Total days

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Weekdays

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Weeks

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Years

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Months

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Hours

Select two dates to see the difference.

Breakdown

History

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Quick Options

Notes

Day counts are based on full calendar days (midnight to midnight). Weekdays exclude Saturdays and Sundays.

Year/month breakdown uses calendar arithmetic (like age calculation), so month lengths and leap years are handled correctly.

Inclusive option adds 1 to the total days so that a range like Jan 1 to Jan 1 counts as 1 day instead of 0.

About Date Difference Calculations

Calendar vs raw days

Raw day differences simply subtract timestamps and divide by 86,400 seconds. Calendar differences (years and months) use actual calendar rules, so February and leap years are handled correctly and the result matches age calculators and professional tools.

Weekdays only

Business date ranges often ignore weekends. Counting weekdays iterates over the range and increments only Monday through Friday, which matches common project planning and working‑days calculations.

Inclusive ranges

When measuring a stay from Monday to Wednesday, many people count it as three days (Mon, Tue, Wed). The inclusive toggle adds 1 to the difference so that the range includes both endpoints, following this intuitive convention.