Add or subtract days from a date
Enter a starting date and a number of days to add or subtract. The result is the new date. Use a negative number to go back in time. Useful for deadlines, scheduling, and planning.
How it works
All date arithmetic uses the browser's native Date object. Day differences are computed by subtracting timestamps and dividing by 86,400,000 ms. Age is broken into complete years, remaining months, and remaining days by comparing each component of the date individually. The page does not call any external library or server during the calculation.
Processing runs in your browser
All calculations happen instantly in your browser tab. Our servers are not involved at any point.
Related operations
For working out an exact age in years, months, and days, try the age calculator. To convert any timestamp into a date, use Unix timestamp. For scheduling work across time zones, see the timezone converter.
Frequently asked questions
- What date is 90 days from today?
- Enter today's date and 90 in the days field to find the date 90 days from now. The tool calculates it automatically.
- Can I subtract days from a date?
- Yes. Enter a negative number to go backward. For example, −30 will give you the date 30 days before the selected date.
- Does it account for leap years?
- Yes. The calculation uses the browser's native Date object, which handles leap years, month lengths, and all calendar rules automatically.