No servers
Inputs remain on your device.
Add or Subtract Dates
Add or subtract years, months, weeks, days, hours and minutes from a date.
Calculations happen locally; dates and time zones are not transmitted.
How to use the add or subtract dates
- 1
Enter the required dates, times or options.
- 2
Select Calculate to run the operation locally.
- 3
Review and copy each format or print the result.
Calendar accuracy in your browser
Explicit rules
Validates ranges, leap years and month changes.
International formats
Uses Intl and IANA to localize results.
Frequently asked questions
What happens when a month lacks the original day?
The result is clamped to the final valid day of the destination month.
Are my dates sent to a server?
No. Every operation runs in your browser.
Which calendar is used?
It uses the Gregorian calendar and dates from years 1 through 9999.