There is a "daylight saving" bit in the data stream from WWV. It notifies your clock the shift is in effect. However the data stream continues on UTC time. Even though each time zone shifts at 2:00 AM local time WWV has to send one common signal to all. I can't find on their web site for which time zone they set the bit.
In the U.S., clocks change at 2:00 a.m. local time. In spring, clocks spring forward from 1:59 a.m. to 3:00 a.m.; in fall, clocks fall back from 1:59 a.m. to 1:00 a.m. In the EU, clocks change at 1:00 a.m. Universal Time. In spring, clocks spring forward from 12:59 a.m. to 2:00 a.m.; in fall, clocks fall back from 1:59 a.m. to 1:00 a.m. In the U.S., restaurants and bars have various closing policies. In many states, liquor cannot be served after 2:00 a.m. But at 2:00 a.m. in the fall, the time switches back one hour. So, can they serve alcohol for that additional hour in October? The official answer is that the bars do not stop serving liquor at 2:00 a.m., but actually at 1:59 a.m. So, they have already stopped serving when the time changes from Daylight Saving Time into Standard Time. In practice, however, many establishments stay open an extra hour in the fall. Bill Ragsdale K6KN
