The rest of the year in which it was achieved/gained, then all of the following year and then the 3 final months, ending on 31st March. So, same system as status through stays/nights/spend direct with Hilton.
This is very helpful. I think I'll hold out for january to do mine. If I request it mid December would it most likely be approved in the new year, or is it best to just request at the beginning of 2020?