[tz] Introduce Etc/UTC+x timezones?

Doug Ewell doug at ewellic.org
Tue May 2 17:31:41 UTC 2023

Benjamin Drung wrote:

> Draft: "Please select the offset corresponding to your time zone.
> Contrary to UTC, positive values to GMT refer to zones west to
> Greenwich and negative values to east to Greenwich (e.g. UTC-6 =
> GMT+6). Time zone: GMT, GMT+0, GMT+1, ..., GMT-9, Greenwich, UCT,
> UTC, Universal, Zulu".

This is exactly how you do NOT want to express it. This is NOT about UTC, the time standard, versus GMT, the time standard.

For purposes of identifying time zones, UTC and GMT are the same thing. They are defined differently and can differ by up to 0.9 seconds, but that is not relevant to the present discussion.

The convention of denoting offsets west of 0° with positive numbers and offsets east of 0°​ with negative offsets is a POSIX thing. It has nothing to do with any differences between UTC and GMT. Telling users it does will only confuse and mislead them.

Tim Parenti’s suggested wording captures the actual issue quite clearly, and I recommend using it. His suggestion to steer users toward geographically based zones and away from the “Etc/GMT±x” identifiers is also recommended.

Doug Ewell, CC, ALB | Lakewood, CO, US | ewellic.org

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