I'm super hopeful this could simply be used in my microwave, stove, car, really anything with a cheap clock in it to sync the time between them to some accurate source, and automatically apply DST.
Most countries have radio signals that transmit the time (including DST). The issue is there has traditionally been no global standard on how it works - each country/region has their own implementation:
Related: this post [1] from the other week on HN, describing a neat little project to build a low-power radio station which emulates the output of radio station WWVB (a fairly well-known station out of Colorado, which transmits the time signal to large parts of North America).
You could build one of those in case you aren't within range of one of the NIST-operated stations :-)
https://en.m.wikipedia.org/wiki/Radio_clock