Add or subtract dates

Here are some ways you could use a formula or worksheet functions that work with dates to do things like, finding the impact to a project’s schedule if you add two weeks, or time needed to complete a task.

Let’s say your account has a 30-day billing cycle, and you want to have the funds in your account 15 days before the March 2013 billing date. Here’s how you would do that, using a formula or function to work with dates.

  1. In cell A1, type 2/8/13.

  2. In cell B1, type =A1-15.

  3. In cell C1, type =A1+30.

  4. In cell D1, type =C1-15.

    cakculate date

Add months to a date

We’ll use the EDATE function and you’ll need the start date and the number of months you want to add. Here’s how to add 16 months to 10/24/13:

use EDATE formula to add months to a date

  1. In cell A1, type 10/24/13.

  2. In cell B1, type =EDATE(A1,16).

  3. To format your results as dates, select cell B1. Click the arrow next to Number Format, > Short Date.

Subtract months from a date

We’ll use the same EDATE function to subtract months from a date.

Type a date in Cell A1 and in cell B1, type the formula =EDATE(4/15/2013,-5).

Subtract months from a date

Here, we’re specifying the value of the start date entering a date enclosed in quotation marks.

You can also just refer to a cell that contains a date value or by using the formula =EDATE(A1,-5)for the same result.

More examples

To add years to or subtract years from a date

Adding and subtracting dates examples

Start Date

Years added or subtracted




3 (add 3 years)




-5 (subtract 5 years)



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