https://groups.google.com/g/mementodatabase/c/JXOFvzeJB_c
rrule
https://support.google.com/calendar/thread/355538328/unable-to-update-recurring-rrule-via-service-account-on-google-resource-calendar?hl=en
Unable to update recurring RRULE via service account on Google resource calendar - Google Calendar...
https://bugzilla.mozilla.org/show_bug.cgi?id=326370
326370 - support for additional RRULE FREQs
RESOLVED (nobody) in Calendar - General. Last updated 2006-02-08.
support foradditional