For those who haven't heard of en_DK before, it's the "European English" (for want of a better description) locale.
It uses Commonwealth English (en_GB) for strings and ISO-14651-1 for collates.
Dates are in YYYY-MM-DD, time is in 24h HH:MM format, Monday is the first day of the week, comma is the decimal separator, currency is euro and standard paper size is A4.
"I appreciate SDF but it's a general-purpose server and the name doesn't make it obvious that it's about art." - Eugen Rochko