Best overlap: 8:00 AM to 12:00 PM in Zurich is 2:00 PM to 6:00 PM in Perth.
The sweet spot is 8:00 AM to 12:00 PM Zurich time, matching 2:00 PM to 6:00 PM in Perth. You've got a decent 4-hour window. Set a recurring time near 8:00 AM in Zurich (2:00 PM in Perth) and stick to it. Heads up: because Zurich changes its clocks and Perth doesn't, the difference moves by an hour twice a year. Confirm the overlap around the DST switch.
| Local time | 12am | 1am | 2am | 3am | 4am | 5am | 6am | 7am | 8am | 9am | 10am | 11am | 12pm | 1pm | 2pm | 3pm | 4pm | 5pm | 6pm | 7pm | 8pm | 9pm | 10pm | 11pm |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Zurich Europe/Zurich | ||||||||||||||||||||||||
Perth Australia/Perth |
The US to Australia gap runs 14 to 19 hours depending on the month, and someone is always in tomorrow. Exact overlap windows for every US coast, the double-DST trap, and a rotation rule that keeps it fair. -