Hello Kyle, Tony,
I don't think the issue is coming from our latest upgrade but from when we did THE upgrade (from the long time running 8251 to 8664 and then a bit later from 8664 to 8747).
However if the setting was present from before these, that would mean someone at our company set it to 12 months while wandering into the admin area.
So it still could be that it's not an issue triggered by the upgrades.
I'm trying to restore a backup of some users dated from end of december 2023, right before we did the upgrade.
I will also restore SM main settings.json from this date to check how was the setting set at this period.
I'll also try your solution, Tony, to re-import older entries in these users calendars.
Thanks!