alt Hacker NewsThe atomic time radio station WWVB does in fact broadcast a daylight saving time bit. A good atomic time clock should accurately update for DST (though Amazon reviews for a clock like this one is pretty mixed: https://www.amazon.com/Crosse-Technology-617-249-Curved-Atom...)
My La Crosse wall clock does support the DST bit, the switch on the back only sets whether you live somewhere that recognizes it or not. Twice a year I try and stay up to watch the clock hands zoomin around during the changeover