Excel already knows when the month ends.

Subtraction is the easiest way to count days between two dates in Excel. You can use the arithmetic operator – (minus sign) to subtract one date from another to find the number of days between them.

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.

Q. I am trying to do some analysis regarding how many clients each of our departments serviced and how many of those clients were billed over a certain amount. I have our department/ client ...

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.