Date in Libreoffice Calc vs Google Docs

I have been annoyed with the date format in LibreOffice vs Google Docs
Uploading a csv file, to a particular cloud based application, made in Libreoffice, fails.

When uploading the same document to Google Docs I find that the date format differs from line to line.
After editing and downloading the csv file from google docs makes it possible to upload the document w/o failure.

I’ve been trying to clean up the date cells in Libreoffice in all different ways w/o succeeding to make the file clean and readable by the system I’m trying to upload it too. But, w/o success…
Does anyone have any idea what to do to make a proper csv file of a date column in LibreOffice?
Thanks for any suggestions.