ISO 2014 explained

ISO 2014 is an international standard that was issued in April 1976, and superseded by ISO 8601 in June 1988.^{[1] [2]} ISO 2014 was the standard that originally introduced the all-numeric date notation [YYYY]-[MM]-[DD] with the digits in order starting with the most significant digit first (similar to big-endian). It was technically identical to ISO Recommendation R 2014 from 1971.

Notes and References

1. Web site: ISO 2014:1976 - Writing of calendar dates in all-numeric form.
2. Web site: 2004-12-01 . ISO 8601:2004(E) . limited . 2006-11-15 . . Annex A … From that concept representations of all other date and time values were logically derived; thus, ISO 2014, ISO 3307 and ISO 4031 have been superseded..