Date Difference Calculator
Precisely count calendar days, weeks (including a decimal part), and calendar months between two dates.
How the date difference is calculated
The calculator determines the exact number of calendar days between two given dates, then shows it in weeks with a decimal part and in calendar months. Leap years are accounted for.
Difference (days) = End date − Start date
The tool is useful for calculating age, work tenure, document validity periods, or the number of days until an event or deadline.
This material is for reference only.
FAQ about calculating dates
Are leap years taken into account?
Yes, the calculation uses the real calendar, so February in a leap year is correctly counted as 29 days.
Can I calculate age from a birth date?
Yes — enter the birth date as the start date and the desired date as the end date to get the difference in calendar days, weeks, and months.
Is the end date included in the count?
The calculator counts the full number of days between the two dates. If you need to include both boundary days (for example, to count vacation length), add one day to the result.
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