Reykjavik is 10.5 hours behind Adelaide
There is no standard 8-to-6 overlap. Someone joins early or late.
When Adelaide starts work, Reykjavik is already winding down or offline — the 10.5-hour gap leaves no shared window. Default to async and only schedule live time when it genuinely needs a conversation — then make it count. For part of the year the maths changes: Adelaide observes daylight saving, Reykjavik does not, shifting the overlap by an hour.