Can a Xiaomi / MIUI phone bet set to use dd/mm date format?
It's less Xiaomi than Android 6, which eliminated the corresponding setting from the settings pages unfortunately. The argument is obviously that those formats are bound to the region, and thus shall be chosen by the language you pick (English/US vs. English/UK,NZ,whatever).

What they obviously forgot is that the number of combinations is limited. No way to chose e.g. English/DE that way, to have English language with German date/time &amp; number formats. Or that one user prefers the year in dates being 2 digit while another wants 4… I was looking for a better solution for weeks, but couldn't find it.

Also see: How to change date and time format on Marshmallow?