Handed down by the ISO, The Great Compromise allows YYYY-MM-DD (or YYYYMMDD if you're in a hurry) but the version with slashes I'd find ambiguous and upsetting, especially early in the month.
The standard is good, and you can get it from `date -I`. Hell mend anyone who messes with the delimiters or writes the year in octal or any other heresy.
https://en.wikipedia.org/wiki/ISO_8601
Handed down by the ISO, The Great Compromise allows YYYY-MM-DD (or YYYYMMDD if you're in a hurry) but the version with slashes I'd find ambiguous and upsetting, especially early in the month.
The standard is good, and you can get it from `date -I`. Hell mend anyone who messes with the delimiters or writes the year in octal or any other heresy.