🗓 YearDay. It’s the hottest new date format in town. Here’s the docs:
The first part is the year and the second part is the day of the year, which goes up to 365 (or occasionally 366) then resets. Dot in the middle.
Months are so last millennium, they were created arbitrarily by the emperors of antiquity. Time is represented by a final dot followed by milliseconds since midnight: 2019.220.123000