So, one thing that I should have learned from trains, but took a little longer to seep in, is that if you wait for all the individual engines to come up with a time you'll get nothing but confusion and delay. You need one person, some sort of controller, to just pick a date and time. Another thing I've learned is that when you're dealing with a global organization there's no time that will work for everyone, and the best thing to do is to get the meeting organized and if it goes well or you need more people, you can have a follow-on meeting at a different time. And finally, I've learned that a concrete proposal gets a decision made a lot faster than a vague one.
So with all that in mind, I'm just going to propose a time: this Sunday the 27th, at 7pm GMT. That ends up being 8am in New Zealand on Monday the 28th, and in the US that's 2pm on Sunday on the East Coast and 11am on the West Coast. Or go here to check your own time zone: https://www.timeanddate.com/worldclock/converter.html?iso=20201227T190000&p1=22&p2=179&p3=136&p4=57 . Of course anyone should feel free to make a counter-proposal!
Not being a regular Zoom user, I'll leave it to someone else to actually set up the meeting itself.