Date Calculator
Find days between dates, add or subtract calendar time, and count weekday-based business days
Calculate dates
Choose a mode, enter calendar dates, then review and copy the exact result
- Choose modeDifference, date arithmetic, or business days.
- Enter datesUse local calendar dates without timezones.
- Review resultRead the summary, breakdown, and weekday.
Choose a date calculation
Each mode uses calendar-date rules without time or timezone shifts
Choose a mode and enter the dates to calculate a calendar result.
Ready to calculate
Calendar dates without timezone shifts
Date Difference measures calendar spans, Add or Subtract applies month-end clamping, and Business Days counts weekdays with explicit boundaries.
FAQs
Is the date difference inclusive?
Total days counts elapsed date boundaries. Business Days separately lets you include or exclude each endpoint.
What happens when adding a month to January 31?
The result clamps to the last valid day of February, including February 29 in a leap year.
Are public holidays removed from business days?
No. The first version counts Monday through Friday only because holidays differ by location and year.
Can the end date be before the start date?
Yes. The result keeps the selected direction and reports the absolute calendar span.
Are leap years included?
Yes. The calculator follows the Gregorian calendar and includes February 29 in leap years.
Can I calculate across different months or years?
Yes. Date Difference works across month and year boundaries and shows the total span plus a calendar breakdown.