time zone updates

But countries do change their DST and/or internal timezone rules.

But what does DST mean?? But why do we have to learn to decipher and memorize these stupid acronyms when it would be enough to write their entire name??

DST is Daylight Saving Time.

I think what is surprising is that time zone updates require a software update.

Other similar data doesn't require user interaction.  For example:

- ephemeris data (sent automatically without user interaction)

- clock (updates according to DST without user interaction)

Also Connect IQ apps update with user interaction.

Countries have been known to decide not to change to daylight savings time literally hours before the change would have happened.

The update to DST is completely driven by the Timezone Database. Without it your watch will not automatically change to summer/winter time.

https://en.wikipedia.org/wiki/Tz_database

https://tzdata-meta.timtimeonline.com/ - all changes since 2016

It's also a bit bigger than the ephemeris data as it will also contain details of geographic boundaries, so probably can't be sent via that mechanism. The boundaries don't always line up with countries or states. For instance, during summer, you could have six timezone changes in 100 miles or so driving across Arizona USA.

en.wikipedia.org/.../Time_in_Arizona