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.

Q. I often create agendas and schedules with a certain amount of time allotted for each agenda item — for example, 10 minutes for introductions, six minutes for each team to propose their ideas, etc.