[tz] Recommendations to governments about time zone update notice period and format

Brooks Harris brooks at edlmax.com
Thu Mar 9 14:39:06 UTC 2023

On 2023-03-08 2:55 AM, Paul Eggert via tz wrote:
> -If your government plans to change its time zone boundaries or
> -daylight saving rules, inform <code>tz at iana.org</code> well in
> -advance, as this will coordinate updates to many cell phones,
> -computers, and other devices around the world.
> -The change should be officially announced at least a year before it affects
> -how clocks operate; otherwise, there is a good chance that some
> -clocks will operate incorrectly after the change, due
> -to delays in propagating updates to software and data. The shorter
> -the notice, the more likely clock problems will arise; see "<a
> -href="https://codeofmatt.com/2016/04/23/on-the-timing-of-time-zone-changes/">On
> -the Timing of Time Zone Changes</a>" for examples.
> -The <code><abbr>tz</abbr></code> data can represent planned changes
> -far into the future, and a long-planned change can easily be reverted
> -or otherwise altered with a year's notice before the change would have
> -affected clocks.
It seems to me something like this should be front and center on the 
main IANA Time Zone Database page:

It seems you'd really like to get this message to the lawmakers and 
authorities who make these decisions. They aren't as likely to learn 
this if the message is buried in the documentation.

Additionally, a link to a page with more details on time zone rules and 
suggested forms of submission to tzdb could help guide those responsible 
for informing tzdb.


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