I'm very confused with multiple moonrise and moonset times across Australia.

For Example (According to https://timeanddate.com)

  • Moonrise in Sydney on 22 Mar 2023 is at AEST 7:09AM which is going to be 4:09AM AWST in Perth. This is when i check the Moonrise and Moonset timings of Sydney

  • If i then change the city to Perth on the website and look at the moonrise time on 22 Mar 2023 it is 6:37AM AWST which is 9:37AM AEST Sydney time.

So according to the above timetable, it feels like moon came out first in Sydney and 7:09AM and then again for Perth at 9:37AM ???


1 Answer 1


Yes. The Earth isn't flat. Sydney and Perth are at different longitudes, so the when the moon rises in Sydney, it is is still set in Perth. The moon rises earlier as you go towards the East. So the moon rises earlier in Tokyo than in Beijing. It is earlier in Berlin then London. It is earlier in New York than LA.

Sydney is 35° east of Perth, and the moon moves at about 14.5° per hour, so you would expect the moon to rise about 2½ hours earlier in Sydney than in Perth, which is exactly what you have observed. (nod to David H)

The same can be said about the sunrise each day. It rises earlier in Sydney and later in Perth

  • 1
    $\begingroup$ In particular, Perth is about 35.35° further west than Sydney in longitude. At 14.5° per hour (the Moon's mean tidal rate), that corresponds to about 2 hours and 26 minutes. $\endgroup$ Commented Mar 17, 2023 at 13:01

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