What would be earliest month in 1941 that the Japanese could have carried out the attack on Pearl Harbor before the December 7th attack of OTL?
If some ass-brained reason Japan decided to go with only 4 carriers, then any time in 1941. Otherwise you have to modify the build/ready time of the Shokaku and Zuikaku. Or they decide to use the smaller carriers.
Damn ninja'd. So yeah, an earlier attack would have mean fewer planes, and only-dive bombers.The earliest would be October, because the modified torpedoes required by Pearl Harbor's shallow depth were not available earlier.
Except that the OP specifically asks about Pearl.Actually as much as Carrier availability is a factor in planning the attack. You have to remember the attack on Pearl Harbor is not an end unto itself. It is a diversion/flank protection for the primary operation, the attack on the Southern Resource Area. When was the shipping and air support available for that attack? That is your earliest possible date. Then, if a Pearl Harbor attack is decided on to support the main attack, then carrier availability becomes a factor in determining the date.
But everything is first determined by the attack on the oil fields, that is the entire purpose of the war...
Except that the OP specifically asks about Pearl.
An attack on the Philippines and DEI could have been done earlier, no doubt. But once they decided that 'a punch to the nose' would get the US to back down/stay out, they pretty much had to do Pearl, and that meant waiting until Dec 7. (Or maybe Nov 30 or so)
Ha, ha. And get promptly assassinated. Nope. Not going to happen.Do the Japanese:
a) Give in to US political demands and withdraw from occupied China because they cannot disable the US fleet in a surprise stroke
b) revert to their pre-Pearl plan of just striking south (including the Philippines) and accepting that any fleet from the US would not be crippled in 1 blow but would have to be attrited and ambushed as it advanced to the western Pacific