Pearl Harbor's carrier turnaround opens a January window

Japan's carrier force sets the counterfactual's operational clock after Pearl Harbor. Its ships need to return to Japan, reorganize, reload, prepare for further operations, and work up before reaching the South China Sea around late January or February 1942. That interval gives a surviving Force Z time to gather ships already in theater and receive plausible January reinforcements. Japan still poses the decisive threat when it turns toward the Dutch East Indies, where the delay could produce a much larger fleet battle.