4 ms·
IMHO the worst mistake in ISO-8601 was flipping the sign on the time-zone offset. I'll never understand why someone decided 02:00+01:00 should equal 01:00Z not
by contravariant 5y ago
IMHO the worst mistake in ISO-8601 was flipping the sign on the time-zone offset.
I'll never understand why someone decided 02:00+01:00 should equal 01:00Z not 03:00Z.
- Arnavion 5y agoI believe the concept of +01:00 meaning 1 hour ahead of Greenwich already existed before ISO8601.
- CodesInChaos 5y agoDefining CET as UTC+01:00 makes sense, because you get the local time by adding an hour to UTC. And then you extend that convention to timestamps, where you include a timezone indicator, not an arithmetic expression.
- contravariant 5y agoWell yeah CET = UTC + 01:00 makes sense. If UTC=02:00 then you'd get CET = 02:00 + 01:00 = 03:00, which all works out nicely. Solving for UTC would then give UTC = CET-01:00. So if you want something equivalent to UTC without explicitly denoting the timezone it'd make more sense to denote 03:00 CET as 03:00-01:00 rather than 03:00+01:00. I mean sure technically you're appending the timezone, but if you omit all the detail that makes it clear that it is a timezone then I just think it looks silly.
- Joker_vD 5y agoBecause it tells you how to go from local time to UTC — and a change-of-basis transformation A from old to new is defined to be such a transformation that x_old = A x_new , not the other way around, x_new = A x_old . So, you have 02:00 in some local time, and you want to go to UTC? The change-of-basis transformation is "add 1 hour", because 01:00 (in UTC) plus 1 hour results in 02:00 (in local time), all perfectly reasonable, from an algebraist's point of view.