On 3/17/22 14:31, Chris Walton via tz wrote:
Yukon recently did the same thing.
When Yukon did that, we modeled that as America/Whitehorse and America/Dawson being on -07 standard time all year, with the abbreviation "MST". This made sense, as that's what "MST" means elsewhere in North America. This new change, if it becomes law, won't be so easy to deal with. It will likely cause "Pacific Time" to be synonymous with -07 and "Mountain Time" to be synonymous with -06 in popular usage, which means that the entries for America/Whitehorse and America/Dawson will need to change from "MST" to something else, as "MST" will be misleading. It's been longstanding tzdb practice to model permanent DST as standard time. Admittedly this practice has so far been employed only for locations like Argentina that have fewer users. Still, the precedent is there and is consistent with the traditional meaning of standard time. There's another issue here: permanent DST is more likely to break software applications. For example, permanent DST in California that is called "PDT" and is 7 hours behind Greenwich would entail a POSIX-style TZ string like TZ='XXX6PDT7,0/0,J365/23' that means "California's standard time is 6 hours behind Greenwich, but it springs backward to 7 hours behind Greenwich on January 1 at 00:00 and springs forward on December 31 at 23:00, so it's actually on daylight saving time all year". I suspect these oddball TZ strings would break applications, and I doubt whether this approach would be wise even if it barely conforms to the standards.