There are some routines inside of UE4 itself, that you can call directly in order to get the time. That would be a much better way I would think, instead of messing around with getting library integrated, and then having to maintain it, etc. I forget the name of the routine right now, or the include files that you need to use. But I know it’s there, it returns the time more as the standard (where 0 time = Epoch Date = 1 Jan 1970). Hence just grab it twice, on button press/release, and subtract.