From 241e6df0731f0e8d2a07a7ac42878f00086bd642 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Thu, 10 Sep 2020 17:48:59 -0700 Subject: [PATCH 32/47] Improve heads-up advice MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit * tz-link.html (Changes to the tz database): Clarify that an official announcement should be made a year before changes affect clocks, and that it’s OK to give more than a year’s notice. From suggestions by Florian Weimer and Robert Elz. --- tz-link.html | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/tz-link.html b/tz-link.html index dfdaece..e6e4acd 100644 --- a/tz-link.html +++ b/tz-link.html @@ -215,13 +215,18 @@ generated automatically. If your government plans to change its time zone boundaries or daylight saving rules, inform tz@iana.org well in advance, as this will coordinate updates to many cell phones, -computers, and other devices around the world. With -less than a year's notice there is a good chance that some +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 computer-based 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 "On the Timing of Time Zone Changes" for examples. +The tz 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.

Changes to the tz code and data are often -- 1.8.3.1