Western Australia had a three year daylight saving trial imposed on us with short notice back around 1999. A decade later it was still dangerous to try to sync a calendar through iCloud from a Mac to a PC running Outlook. And I discovered a couple of years ago that Yealink VOIP phone still get the time wrong here during summer.
Oh man, so that's why?? I remember working on an issue for a client in Perth where their calendar was out of sync by an hour, and yep it was iCloud connected to Outlook on Windows. Being based in Victoria, I had never heard of WA's flirt with daylight savings time, but that totally explains the gremlins I was seeing.
