The en_DK locale is a hack on locales; I suspect it's named so for the dose of humor. Various Linuxes have adapted en_DK as a kludge which has the english dictionary and charmap but various European or international date/time formatting. Since it was refused in FreeBSD for reasons of purity over user convenience, I guess everyone has to roll their own now.
Since I need that situation, I rolled my own en_DK-UTF-8 locale. The archive should be extracted in /usr/share/locale. It has the following features:
- Plain english UTF-8 encoding / collating
- Euro (€) as currency
- 24 hour time
- day-month-year for many common formattings
- Y-m-d for the "long" format
The last two items - date/time formatting may not fit everyone because it's such a mix. I'm not sure it fits even my purpose but I'll leave it at that for now.