📅 Date Adder — Add or Subtract Days from a Date
Pick a start date, enter how many days to add or subtract, and see the new date with its weekday. All calculation stays on your device.
Input
Result
Details
Private by design. This tool runs entirely in your browser — nothing you enter or add is uploaded to any server.
How it works
- Select or enter a starting date.
- Enter the number of days to add (use a negative number to go backwards).
- Click Calculate to see the new date and its weekday.
Examples
- A project deadline is 45 days from today — enter today and 45.
- Find the date 90 days before a birthday for a reminder.
- Calculate the end date of a 14-day free trial.
Frequently asked questions
Does it handle leap years and month lengths correctly?
Yes. It uses the browser's built-in Date object which correctly accounts for leap years and varying month lengths.
Can I subtract days?
Yes. Enter a negative number in the days field to go backwards in time.
Is the calculation private?
Yes. The entire calculation runs locally in your browser; no dates are sent to any server.
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