Finance tutorial: how to calculate present value & net present value using Excel (Windows or Mac, any version) or Google Sheets. The full article, practice file and screencast is available for free on TutsPlus. Or you can watch just the screencast here:
Between the Sheets — Excel podcast episode 31: Excel’s secret DATEDIF function
A quick and simple way of finding the number of days, months or years between two dates is Excel’s secret DATEDIF function. When you type it in a worksheet, there’s no popup syntax help to indicate the function exists.