Negative Numbers...illogic ...why ?

[Nico cerrere]

Hello,

I'm in a hurry to pass my Looker Studio Exam.

I would like to calculate the time passed for each delivery (departure time of each truck from the datawarehouse)

I enclose the file with my formula and you will see the negative time !!

A csv file is the base. Initially it was recognize in String, now it is DateTime, I forced it.

The same format is forced in the resource menu : see attached file.

Thanks for helping me !!