Thanks for the clarification.

The answers from @Manel Trèmols and @Ramil TK should both work for you.

You might have to do some additional formatting depending on what datePart you getting the difference in. For example if you get the difference in Minutes ("n"), then you will have to convert that into Days, Hours, Minutes etc, so it will depend on what you are expecting in the data and how big those differences might be.