[quintushoratius]

Not every region of the continental US respects DST.

[lxgr]

I know, but if it does, it switches on the same day as all the others, which could be encoded in the signal, and it seems like it is [1].

So instead of a switch to “add an hour”, there could be one that says “add an hour if the signal says DST is currently in effect”.

[1] https://en.wikipedia.org/wiki/WWVB#Amplitude-modulated_time_...