I think it’s “May 15” in spoken English? It would be “15th May” in Swedish and Farsi for instance.

Therefore: Swedish, Farsi > English

I prefer SSSSSSSSSSSSSSSSS because what can be more accurate and objective??

If most of the dates you’re looking at are within a reasonably narrow span (say 90 days), DD.MM.YYYY gives you the important information first, and you can often omit the YYYY entirely.