Swatch Internet Time (en.wikipedia.org)

I was a fan since MCP (a super bag of hacks and goodies for AmigaOS) came with a way of putting @123 next to your date. I even "reimplemented" it for fun and wrote a blog about it. You probably can't read it since it's in Polish:

https://fuse.pl/beton/umowilem-sie-z-nia-na-833.html

https://git.sr.ht/~bronikowski/pyswatch — it still lives in my tmux's status bar.

>PHP's date() function has a format specifier 'B' which returns the Swatch Internet Time notation for a given time stamp

That is pretty funny