The IF function returns different outputs depending on whether the criteria are met. If Part 2 returns TRUE (in other words, ...

When you enter a number into an Excel cell that looks like a date, such as "Jun-1" or "6/1," Excel automatically adjusts the format of the cell to display a date, so you may not know that Excel ...

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.