Sequence of Events
Saturday, December 6 - Washington D.C. - U.S. President Franklin Roosevelt makes a final appeal to the Emperor of Japan for peace. There is no reply. Late this same day, the U.S. code-breaking service begins intercepting a 14-part Japanese message and deciphers the first 13 parts, passing them on to the President and Secretary of State. The Americans believe a Japanese attack is imminent, most likely somewhere in Southeast Asia.
Sunday, December 7 - Washington D.C. - The last part of the Japanese message, stating that diplomatic relations with the U.S. are to be broken off, reaches Washington in the morning and is decoded at approximately 9 a.m. About an hour later, another Japanese message is intercepted. It instructs the Japanese embassy to deliver the main message to the Americans at 1 p.m. The Americans realize this time corresponds with early morning time in Pearl Harbor, which is several hours behind. The U.S. War Department then sends out an alert but uses a commercial telegraph because radio contact with Hawaii is temporarily broken. Delays prevent the alert from arriving at headquarters in Oahu until noontime (Hawaii time) four hours after the attack has already begun.
Sunday, December 7 - Islands of Hawaii, near Oahu - The Japanese attack force under the command of Admiral Nagumo, consisting of six carriers with 423 planes, is about to attack. At 6 a.m., the first attack wave of 183 Japanese planes takes off from the carriers located 230 miles north of Oahu and heads for the U.S. Pacific Fleet at Pearl Harbor.
Pearl Harbor - At 7:02 a.m., two Army operators at Oahu's northern shore radar station detect the Japanese air attack approaching and contact a junior officer who disregards their reports, thinking they are American B-17 planes which are expected in from the U.S. west coast.
Near Oahu - At 7:15 a.m., a second attack wave of 167 planes takes off from the Japanese carriers and heads for Pearl Harbor.
Pearl Harbor is not on a...