I’ve looked into this a little bit more, the Time Zone list comes from the server.
timedatectl list-timezones
If your timezone isn’t listed there, you’ll need to select the next nearest city I believe. Lifeboat sets the timezone this way to keep things like Daylight Savings synchronized correctly (I know, I know, them Americans). When I built the feature I wasn’t sure if setting an offset by hour broke that or not.
Unless I’m misunderstanding the other issues seem like Xojo Framework issues.
Hopefully this helps, please let me know if there’s anything else I can do.