Didn’t someone in Washington deduce from intercepted Japanese diplomatic messages that an attack on Pearl Harbor was imminent and send a telegram, but because of it being a weekend there were delays and the message was delivered to the commander at Pearl Harbor after the attack had already started?
(While this doesn't directly answer your question, I have to point out as an aside that on 11/27/41, Kimmel had received a message from the Navy Department that began with the lines, "This despatch (sic) is to be considered a war warning. Negotiations with Japan looking toward stabilization of conditions in the Pacific have ceased and an aggressive move by Japan is expected within the next few days.")
The telegram you describe appears to pertain to the message sent by General Marshall to Pearl Harbor on 12/07/41 at 1300 EST/0800 HST that described a 14-part decrypted communiqué sent to Japanese diplomats in DC that they were to destroy sensitive codes and paper. This message from Japan was decrypted overnight from 12/06/41 until 12/07/41; instructions were given from the codebreakers to have it delivered at the time described (1300/0800). It has to be noted that the message sent to Hawaii was not an explicit warning of a specific attack, and it arrived minutes after the Japanese attack had commenced. It has to be noted as well that this communiqué was not delayed because of the weekend; it was sent via commercial cable, due to concerns about secrecy and delays.
(You would probably be aware that the military in Oahu was practically screaming for more raw intelligence, but the information that was being decrypted and processed back on the east coast was nothing more than noise; the military could forward it to Oahu, but without intelligence behind it, it would take the perfect reading of the evidence to piece together that an attack was coming at 0800 HST on 12/07/41. I have never come across any information that would indicate such a direct message warning of a Sunday AM attack had been sent [whether on time or tardy].)