|This article is speculation.|
|None of the mentioned details are confirmed.|
World War IV is an event that happens prior to the events of Cinder.
It is possible that it happens very distantly to now, 2990+ as 1 T.E (Third Era) is the first year of peace, the year 3000. Although, this could be farther away as they reset their years system. It could be hundreds of thousands of years in the future.