Passage: On October 26 at 6:00 pm EDT, the State Department started receiving a message that appeared to be written personally by Khrushchev. It was Saturday at 2:00 am in Moscow. The long letter took several minutes to arrive, and it took translators additional time to translate and transcribe it.Robert F. Kennedy described the letter as "very long and emotional". Khrushchev reiterated the basic outline that had been stated to Scali earlier in the day: "I propose: we, for our part, will declare that our ships bound for Cuba are not carrying any armaments. You will declare that the United States will not invade Cuba with its troops and will not support any other forces which might intend to invade Cuba. Then the necessity of the presence of our military specialists in Cuba will disappear." At 6:45 pm EDT, news of Fomin's offer to Scali was finally heard and was interpreted as a "set up" for the arrival of Khrushchev's letter. The letter was then considered official and accurate although it was later learned that Fomin was almost certainly operating of his own accord without official backing. Additional study of the letter was ordered and continued into the night.

Question: How long was the study continued?
into the night