➕📅 Add or Subtract Days from a Date
Add or subtract any number of days, weeks, months, or years from a date to instantly find the resulting date.
Start Date & Adjustment
Result
How This Calculator Works
This calculator moves forward or backward from a start date by a chosen number of days, weeks, months, or years, using calendar-accurate arithmetic — so adding a month to January 31 correctly lands on the last valid day of February rather than rolling over incorrectly.
Formula
Months/years preserve the day-of-month where possible, adjusting for shorter months
Worked example: Adding 90 days to January 1, 2026 lands on Wednesday, April 1, 2026.
Frequently Asked Questions
What date is 90 days from today?
Enter today's date as the start date, choose "Add," enter 90, select "Days," and the calculator instantly shows the resulting date and day of the week.
What happens when adding a month to the 31st of a month?
If the target month is shorter (e.g. adding one month to January 31), the date is adjusted to the last valid day of that month (e.g. February 28 or 29).
Can I subtract time to find a past date?
Yes — select "Subtract" as the operation to move backward from your start date by any number of days, weeks, months, or years.