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, WORKDAY, ...

As you create Excel spreadsheets for your small business, time and date functions frequently add both convenience and programming capability to your workbooks. There's good news with date functions.

DATEDIF(), which means Date + Dif, is a compatibility function left over from Lotus 1-2-3 that Microsoft adopted in Excel version 2000, which is the only version that explains how this function works.