Add or Subtract Days From a Date

What this tool does

This calculator shifts a date forward or backward by a set number of days and tells you exactly where you land. You pick a starting date, choose whether to add or subtract, enter how many days, and it returns the resulting date along with its day of the week. It is useful for working out deadlines, due dates, delivery windows, notice periods, warranty or trial end dates, follow up reminders, and any planning where you need to know what date falls a certain number of days away.

It counts plain calendar days, so weekends and holidays are included and leap years are handled automatically. That makes it a fast way to answer questions like what date is 30 days from now without counting on a calendar by hand.

How to use it

1. Click the Start date field and choose your starting date.
2. Set Operation to add or subtract, depending on the direction you need.
3. Enter the number of Days to move.
4. Press Calculate.
5. Read the result: the new date plus its day of the week.

A quick worked example

Say you start on June 1 and need to know the date 30 days later. Set Start date to June 1, set Operation to add, type 30 into Days, and press Calculate. You get July 1, a Tuesday, so you can see both the date and the weekday at a glance. To go the other way, switch Operation to subtract and the tool steps backward instead.

Everything runs right in your browser, so the dates you enter stay on your device and nothing is sent to a server. It is free, private, and needs no sign-up.