Wall time or instant?
A recurring meeting has to be anchored to something. Anchored to local clock time, it stays at 09:00 in the organiser’s zone and moves for everyone whose clocks change on different dates. Anchored to an instant, it repeats every 7 × 24 elapsed hours and stays put in UTC, so the organiser’s own clock time shifts by an hour after a DST change. Pick one deliberately; the table marks occurrences whose local time moved.
Exceptions
If an occurrence falls in a skipped hour you can skip it, shift it forward, or shift and flag it. Repeated hours use the first or second occurrence. You can also exclude individual dates; excluded dates are kept as exceptions and restored with one click.
Export and rule changes
The .ics export writes each occurrence as its own event with a stated horizon instead of an open-ended rule, so calendar apps cannot reinterpret it. Save a snapshot of accepted occurrences; after a browser or OS update you can recompute and see exactly which occurrences would move before changing anything.