DST changes are pre-scheduled. Throwing a random hour in/out at (say) June 30, 2029 may be something else. Unless the jump is treated as a TZ change in tzdata?
Yeah you treat it as a time zone change where every zone moves over (or every country moves to the adjacent zone maybe). You can schedule it N years in advance. It's definitely not 0 disruption, but it's very manageable. Regions change TZs or toggle DST frequently enough that we can handle it.
