Re: [POLL] Proposed syntax for timestamps with time zone info

[Jean Louis]

* Stefan Nobis <stefan-ml@snobis.de> [2023-02-01 12:13]:
> <tomas@tuxteam.de> writes:
> 
> > 2023-03-23 02:30 @Europe/Berlin refers to /two/ points in time, thus
> > it /is/ ambiguous.
> 
> As far as I understand the definitions, the point in time "2023-03-23
> 02:30 @Europe/Berlin" is clearly defined as 2023-03-23 02:30 UTC+0100.
> 
> A bit more problematic would be "2023-03-26 02:30 @Europe/Berlin".
> Strictly speaking, this point in time does not exist, because in the
> night from 2023-03-25 to 2023-03-26 the clock will jump from 02:00
> directly to 03:00 in the time zone Europe/Berlin. Therefore the
> /interpretation/ of this timestamp is ambiguous.

Thank you!

The generation of invalid time stamps is programming bug.

> The real problem would be e.g. "2023-10-29 02:30 @Europe/Berlin". This
> point in time really exist twice, there is 02A:30 (02:30 UTC+0200) and
> 02B:30 (02:30 UTC+0100) in this night of switching back from DST to
> normal time!
> 
> So, in general, only using the time zone name may indeed lead to
> ambiguous interpretations of timestamps.

Exactly! Thank you!

With the correction that "this point in time really exists twice" --
well, not like that, you have specified 2 different time points by
specifying different UTC offset, so those are different time
points. Though I got your ▲

-- 
Jean

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