Microsoft Excel 2010 provides a formula for calculating the average value from multiple worksheets in a workbook. Before you apply this formula, check that each worksheet is formatted the same way.

We show you how to use Excel to count days between two dates using the DAYS, DATEDIF, NETWORKDAYS, and TODAY functions, and Subtraction.

To ensure that Excel converts your date to a number enter it like this, without quotes: "4/4/2011". Then click on cell "A2" and enter the later of the two dates in the same manner.

Learn how to calculate simple, weighted and exponential moving averages in Microsoft Excel using Data Analysis Tool Pack or Formula.

Fortunately, Excel offers a built-in function, DATEDIF, which makes it easy to calculate elapsed calendar time. I sent Zee a sample solution, and she wrote back that it was exactly what she had in ...