One of the many features of Excel is being nosy. That's right, you can quickly calculate a persons age as long as you have their birth date.

The payback period is the amount of time needed to recover the initial outlay for an investment. Learn how to calculate it with Microsoft Excel.

The screen shots were captured using Excel 2000. However, the process is identical in Excel 97, 2000, and 2002. The easy part: Age in days ...