ISO 2014
ISO 2014 is a date format. It specifies writing Gregorian dates' units (year, month, and day) in big-endian order (most significant unit first, least significant unit last), with the units separated by hyphens. For example, Yuri Gagarin became the first person to travel to outer space on 1961-04-12.
Punctuation aside, this is consistent with the Asian date format, rather than the currently more popular European, African, and South American format (which is comparatively backwards), or US format (which is comparatively all over the place).
ISO 2014 format dates are consistent with the ordering of digits within each unit, which are always big-endian regardless of the date format. They're also inherently alphabetised into chronological order, making them a sensible choice on a practical as well as theoretical level.