Calculate future and past dates.

Q. One of my monthly tasks is to calculate contract expiration dates. If I know a contract will expire in nine months from a given date, for example, can Excel figure out the actual expiration date?

A. The EDATE function, when linked with the NOW function, can do that. If you want to know a date nine months from today, use the formula: =EDATE(NOW(),9).

If you want the date nine months ago, use a negative number in the formula, such as: =EDATE(NOW(),-9).

Caveat: If your answer is a five-digit number instead of a date, it means you failed to format the cell correctly. To prepare a cell to exhibit its answer as a date, right-click on the cell to bring up the format screen (see screenshot below) and select the date format you want. The result will be the screenshot on the right.

[ILLUSTRATION OMITTED]

In the unlikely event EDATE fails to work, you probably haven't enabled Analysis ToolPak, which is usually in Excel but by default isn't enabled. To turn it on, click on Tools, Add-Ins. One of the options will be Analysis ToolPak. Click on it and then on OK.

If Analysis ToolPak is not among the options, it probably wasn't installed when Excel or Office was first loaded on your computer. In that case, you'll have to reinstall Excel from the original disks. When you do, be sure to install the Excel add-ins when the option is presented.

Key to Instructions

To help readers follow the instructions in this article, we use two different typefaces:

* Boldface type is used to identify the names of icons, agendas and URLs.

* Sans serif type shows commands and instructions users should type into the computer and the names of files.

STANLEY ZAROWIN, a former J of A senior editor, is now a contributing editor to the magazine. His e-mail address is [e-mail].