Thanks Arthur,
when you work on the Exif/XMP tags you could also cross-check the this Bug: PL5 - wrong TimeZone on export
In my case DXO (starting version 5.0) is always writing “OffsetTimeOriginal” = +00:00 instead of using the correct timezone (like +01:00 or +02:00). The Tag “OffsetTime” is written correctly. I guess/hope this is also something that can easily be fixed.