There's one more test: the Thailand test. I've been bitten by issues in Java where Calendar.getInstance() will return a Thai Buddhist calendar, which is exactly the same as the Gregorian calendar except 543 years in the future.
No, you can't really, especially if the recurring meetings go on more than a few years into the future. If the time zone rules themselves change (e.g. if the user's country abolishes or introduces DST), then the timestamps you stored will become wrong in light of the change.