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.

How to Calculate Fluctuations in Excel. Calculating data fluctuations-- also called variance -- is a multi-step process that requires total accuracy. Excel 2010 provides two basic formulas for ...

To calculate the age, the DATEDIF function, set to check year, determines the number of years between the date in the DOB cell and the current date.

Fortunately, Excel offers a built-in function, DATEDIF, which makes it easy to calculate elapsed calendar time.

Additionally, Excel provides functions to calculate the number of days until a specific date, which is particularly useful for tracking deadlines and managing projects.