ical and hence calendar invites and calendar generally use UTC time with an offset to set the timezone.

SO if you set the appointment for the correct time where you are (say 2pm) the invites will go out showing the meeting to be at UTC8pm −06:00. So your folk in UTC -5.00 will see a meeting at 1pm. Folk in London will be advised of a meeting at 8pm. Anyone getting the invite will see the time relevant to their timezone. The tricky bit is not allowing for the timezone time shifting. So even though the person you are talking to on the phone in Washington says we will meet at one, you have to set it up for 2. I am not aware of a way to specify the event timezone in the event creation.

I will try this with the next one I do. I put a note in the "Description" box, but folks don't always read that, unfortunately.

As far as trying to specify the event time, I had changed the circled time zones in the example below, which didn't work as I noted. The bad thing is when one is sending this to several people who are currently in different time zones, but who will all travel to the second location. I am guessing that there is no way to deal with that confusion, which is not unique to Thunderbird as I saw the same problem with Outlook when I had to use that at work.

Thank you! Michael