That actually works! I didn't realise using the import wizard would be different to just double-clicking the CSV file. I'll still argue that Libre Office Calc'

That actually works! I didn't realise using the import wizard would be different to just double-clicking the CSV file. I'll still argue that Libre Office Calc's workflow is better at this, in that it presents you with a wizard when you double-click the file and by default does not transform something to a date. But I now have an instruction to give to others who come up against this problem, so thank you.