On what date did the United States declare war on Japan after the Pearl Harbor attack?

The United States declared war on Japan on December 8, 1941, one day after the Pearl Harbor attack.

President Franklin D. Roosevelt asked Congress for a declaration in an address delivered to a joint session on December 8. Congress approved the declaration the same day, formally placing the United States at war with Japan.

The declaration followed the Japanese attack on Pearl Harbor and other Japanese attacks across the Pacific and Asia. The United States did not declare war on Germany or Italy immediately; those countries declared war on the United States on December 11, and Congress responded with declarations against both.

The date is often confused with December 7, the date of the attack itself. December 8 was the legal and political response in the United States, while December 7 was the day of the Japanese assault in Hawaii.