Looking at the code [1], it looks like if the actual time is 1 hour ahead of the displayed time, then we get 10 pulses per second to leap forward. Otherwise, the clock stops running for an hour to fall back.
You have two choices: either assume everyone is asleep at 2 am and won't notice when it happens, or else advance 11 hours. My LaCrosse clock does the latter.
I remember clocks in my school would sync up by all running forward to 12 at noon (and presumably midnight). I don't know if it was a radio or wired signal.
And that's pretty much fine for a project like this, seeing as most (all?) locations jump you between DST and not DST at night. So the clock will be off at most for an hour during the night.
Looking at the code [1], it looks like if the actual time is 1 hour ahead of the displayed time, then we get 10 pulses per second to leap forward. Otherwise, the clock stops running for an hour to fall back.
https://github.com/jim11662418/ESP8266_WiFi_Analog_Clock/blo...