8 hrs after the plane left Sydney, it would be 10:25 pm, local.
The only place on earth it would be 4:16 pm, when it's 10:25pm in Sydney, is in the time zone running east of Africa, in the middle of the Indian Ocean
It's 4500 n. miles from Sydney to say, 800 miles east of Madagascar, Africa. That's about as far as you would fly in 8 hrs. And it might be where Yemi's plane would get to as well, flying east from Lagos.
http://www.davidsemporium.co.uk/__GMT.gif
So...they're either in actually in the Indian ocean, or...on another planet.