Excel’s Date & Time functions ease the workload for bookkeepers, project planners, HR departments, and other jobs where time is money. The four functions covered here—ISOWEEKNUM, WEEKNUM ...

How to Make a Cell on Microsoft Excel With a Changing Date. Microsoft Excel offers a Function Library with formulas that insert the current date when you open the worksheet or enter calculations.

DATEDIF (), which means Date + Dif, is a compatibility function left over from Lotus 1-2-3 that Microsoft adopted in Excel version 2000. It's fallen off current Excel menus, but you can still use it.