Date calculator

Date calculator features

• 01

  Two modes, one tool

  Switch between Difference (days between two dates) and Add/Subtract (shift a date by any amount). Both modes show the weekday of the result and a human-readable calendar breakdown.

• 02

  Business days included

  When counting days between two dates, the tool also shows working days (Monday–Friday) — handy for project deadlines, contract dates, and pregnancy or parental leave planning.

• 03

  Handles months and leap years correctly

  Adding one month to 31 January rolls forward to the last day of February, and leap years are respected. No off-by-one errors, no floating-point day-math surprises.

Date calculator FAQ

How many days are between two dates?

Pick Difference mode, choose the earlier and later dates, and the tool shows the total days, weeks, business days and a calendar breakdown in years, months and days.

How do I add or subtract days from a date?

Switch to Add/Subtract mode, set the start date, choose add or subtract, and enter an amount plus a unit (days, weeks, months or years). The result date, its weekday and the difference from today appear instantly.

Does it count business days?

Yes. In Difference mode, the business-days stat counts only Monday through Friday, excluding weekends. Public holidays are not subtracted because they differ by country.

Does it handle leap years?

Yes. The tool uses the browser's native date engine, which respects the Gregorian calendar including leap years, so February 29 is handled correctly.

Are my dates sent to a server?

No. The date calculator runs entirely in your browser. Nothing you type is uploaded, logged or stored.

Is the date calculator free?

Yes. No account, no ads inside the tool, no usage limits — every Handytool is free to use.