- It’s human readable but also succinct
- It sorts correctly
- It includes fractional seconds, which can help re-establish chronology
- It conforms to ISO 8601
- ISO 8601 has been well-established internationally for more than a decade
- ISO 8601 is endorsed by W3C, RFC3339, and XKCD
That being said, every date library ever written can understand “milliseconds since 1970”. So for easy portability, ThiefMaster is right.