Ok, can I just add a comment here, I know what it says in the OMA, but it is interpreted differently by the company, at least in my experience.
I was doing a SFO, the other rostered captain had come back from Australia from leave, had arrived in Dubai 18 hours prior to the flight.
During the pre flight briefing, the FDM called to say he had been removed from the flight as he was not acclimatised.
A reserve captain was sent.
What I never understood ( but I knew the reason) , is why you don't need to be acclimatised at the the other end of a ULR before you start the trip home.
Anyway, I know what the rules are, but I think it is who is interpreting that matters.