Yom Kippur is one of Israel feasts, which is Day of Atonement. Egypt and Syria declared the war against Israel on that day for reasons stated by Mohammed Abd Al-Ghany Al-Gamasy chief of operations of Egyptian Army during the war in his memoirs saying: ( We made a study in the operations organization in the light of the military situation of the enemy and of our forces, the idea of the planned attack operation, the technical specifications of "Suez Canal" in respect of the ebb and tide. We studied all months of the year to choose the best month to thrust the canal in the light of the state of the ebb, tide and the speed of the current and its direction. The study included also all official holidays in Israel other than Saturday, their weekly holiday, as the enemy forces will be less ready for war. We found that they have eight feasts, three of them in October: Kippur day, Sukkot and Rosh Hashana. Our concern was to know the effect of every holiday on procedures of mobilization...