Hi,
You don’t need to edit any preference files to change the time zone in Calendar. You can adjust it directly in the app:
- Open the Calendar app.
- Go to the menu bar and click Calendar > Settings (or Preferences if you’re on an older macOS).
- In the Advanced tab, make sure Turn on time zone support is checked.
- Once that’s enabled, you’ll see a time zone selector in the top-right corner of Calendar. From there you can set Eastern Australian Time (Sydney, Melbourne, etc.) as your default.
Unfortunately, you can’t remove Central European Time completely from the list—it always shows your system’s current region plus any you’ve used. But by turning on time zone support and setting Eastern Australian Time, that will become the active one for new events.
If you’d like Central European Time not to appear at all, the only workaround is to make sure your Mac’s system time zone (under System Settings > General > Date & Time) is set to Eastern Australian Time. Calendar will then use that as the default.