Post #977266
2025-09-24 11:45 UTC
So @sotolf reminded me of something I kind of love. The Japanese "30-hour system". Used in nightlife, broadcasting, and transport, the time extends the day past midnight to keep late-night events grouped with the same calendar day. So a club open from 11PM to 1AM might list its hours as 23:00–25:00.
We should all adopt this!
Sadly Wikipedia does not have a detailed page on this system in English but here is a little longer explanation:
https://skdesu.com/en/30-hours-from/
#Japan #30HourClock #TimeTrivia
Replies (4)
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@ruari@velocipederider.com 2025-09-24 11:49
I was told by a colleague that NASA sometimes use extended hour formats (like 25:00 or 26:00) to keep events grouped on the same operational day. So it is kinda the same as the Japanese 30-hour system. I cannot find a great article on this but if someone knows of one, let me know. 😉
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@astridpoot@mastodon.social 2026-04-05 16:42
@vasilis 😊
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@mack505@feistycricket.org 2026-04-05 19:39
@ruari @sotolf Won’t help me. My shifts run from 07:00 to 31:00.
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@niallor@mastodon.ie 2026-04-06 05:54
@ruari @sotolf I remember from the 1970s that Thomas Cook used such a system. I have no idea how many hours it stretched into the following day.