@simon great intro to a deep rabbit hole, reminds me of my last long-duration "real job" where we budgeted 2 months for "DST fixes" to the calendar and spent 13 months rewriting the core logic to store something we named "intent time"... this was for groupware which absolutely did have calendar events in weird locations with attendees from all over the world. pretty sure I ran the risk of getting fired on that one, but calendar bug calls to support were nearly eliminated.