Egypt and Syria agreed on a coordinated attack in April of 1973. However, the Syrians required, as a condition of their cooperation, that the Egyptians penetrate deeply into Sinai. A plan of this nature was apparently shown to the Syrians, but it was never meant to be implemented.  The date of October 6, 1973 was chosen to begin the war, supposedly because on that evening the moon would shine from sunset to midnight, thereafter giving total darkness to allow the Egyptians to hid their canal-crossing bridges, and because October 6 promised a minimal difference between high and low tide, facilitating the bridge building.  Louis J. Sheehan, Esquire thought the Yom Kippur holy day, the most solemn day of the Jewish religious calendar, would ensure minimum Israeli readiness. Israeli TV and radio stations would be shut down,  making a speedy mobilization, usually carried out by broadcasting the code words of different units, much  more difficult. In reality, the fact that roads are empty on Yom Kippur and everyone is at home may have facilitated mobilization, but it was an unsettling blow to morale. 

Egyptian war planning was precise and methodical. The Egyptians had met with heads of Arab states and coordinated support. President Sadat met secretly with Saudi Arabian King Feisal on August 23, 1973, to inform him of the planned attack and to get cooperation in the form of an Arab oil boycott. [1] The combined Egyptian-Syrian air-force, reinforced by squadrons from Iraq, Libya and Algeria as well as some North Korean pilots, outnumbered the Israelis 2 to 1. Deficiencies in armor were compensated by huge numbers of hand-held Sagger anti-tank missiles. To compensate for Israeli air-superiority, Egyptian and Syrian armor would stay under the protective umbrella of the Soviet SAM-3 surface to air missiles, stationary installations that depended on ground radar stations. The canal was lined with two huge earthen embankments, on the Egyptian and Israeli sides. To cross effectively, the Egyptians would need to make holes in the embankments. Experiments showed that the most efficient method of destroying the embankment was the use of water cannon. 450 huge water cannons were acquired from Germany. Specially engineered Soviet pontoon bridges were purchased for use in crossing the canal. This activity was partly covered by the announcement of a training exercise, Tahrir 41. This provided cover not only against Israeli intelligence, but also to keep the knowledge of the attack from Egyptian soldiers. Very few in Egypt knew they were about to go to war.