1] Add days directly If the expiry period is defined in days, you can calculate the expiry date by simply adding the number of days to the starting date using the + operator.

A TechRepublic member wrote for advice on calculating the years, months, and days elapsed between two dates. This tutorial explains the solution provided by TechRepublic contributor Jeff Davis.

Learn how to calculate the Simple Interest in Excel either for a single entry or a range or entries, between two dates, using this forumula.

Percentages aren't always easy to calculate, but one of the best tools in Excel's toolbox is calculating percentages for you. Here's how to do it.

Follow along in this step-by-step guide to learn how to easily calculate hours worked in Microsoft Excel.

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.

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.