Add/Subtract Date Calculator
Add or subtract days, weeks, months, or years from a date. Enter your values, click Calculate, and get the full result with its breakdown — everything is processed on your device, nothing is sent to a server.
All calculations run in your browser. Your data is never sent to our servers.
Example
Example Input
2020-01-01 + 30 days
Example Output
2020-01-31 (Friday)
How to Use
- 1Fill in each input field with the values you want to compute.
- 2If there are choices (units, mode, operation), pick what you need.
- 3Click the Calculate button (or press Ctrl+Enter).
- 4The main result and its breakdown appear in the Result area. Click Copy to copy it.
About the Add/Subtract Date Calculator
The Add/Subtract Date Calculator computes a new date by adding or subtracting a duration (days/weeks/months/years) from a start date. It handles month lengths and leap years correctly, and shows the resulting weekday.
Useful for deadlines, due dates, and schedules.
FAQ
Is this Add/Subtract Date Calculator accurate?
Yes. It uses standard formulas and runs directly in your browser at full JavaScript precision (plus BigInt/decimal.js for large numbers where needed).
Is my data sent to a server?
No. All calculations happen entirely on your device. No values are sent to or stored on our servers.