English is the only one with conflicting date formats I can think of (US vs UK), but in case of government and corporate documents, those are sometimes bilingual - with form labels in the primary language having a small-font translation to English below.

(Real use case: I recently sent a Polish equivalent of OSHA form to my line manager in UK, and I used a bilingual version. As you can imagine, I set the example by filling my part of the document using ISO 8601 for dates, so that once the document returns to the Polish corporate office, there won't be any possible confusions.)