The variant "2050" stands for "not before 2050".

Trigger 1:

An official declaration/resolution/classification of the conflict as a world war by a recognized international body (UN, EU, NATO, ASEAN, Organization of American States, Arab league, Commonwealth of Nations, etc) .

Resolves to the date of such declaration/resolution.

Trigger 2:

Wikipedia community has a consensus and updates WW3 article accordingly.

Resolves to the date of the start of the conflict, written in the article.

One trigger is enough for the resolution.