I'm looking for advice on how to secure the 2 business class seats for Jan 2022 on a popular route to South Africa

Any advice is appreciated,

What is the best tactic for aiming for the 2 business class tickets which are released 355 days out? - I understand it is phoning the call centre.
Is it phoning the US call center or Japan?
Is the relevant timing GMT (not BST or something like that)?
How long before midnight (at the international date line?) should I try to call?
Is it awkward? Are agents used to this sort of thing? I imagine I might be asking them to refresh a few times.
Anything specific I should ask for? - I.e. that they immediately reserve the tickets?