The Arab-Israeli War in 1973, besides the Jewish Holiday, also took place during the Islamic holy month of Ramadan, during which practicing Muslims observe mandatory daytime fasting. Did this affect the performance of the Arab (Egypt and Syrian) armies? I'd think hungry or dehydrated soldiers may not fight or think as well as when they're well fed. Why did the Arab leaders decide to attack during this period?
Reasons for Arabs starting the war during Ramadan:
Arab attacked Israel on October 6, 1973. That year, October was the month of Ramadan. But the main reason for attack on this day was Yom Kippur festival, which was on this day. Yom Kippur also known as Day of Atonement, is the holiest day of the year for the Jewish people.
Arabs were defeated in all previous wars with the Israel.
So, Arab (Egyptian and Syrian) military forces launched an attack knowing that the military of Israel would be participating in the religious celebrations associated with Yom Kippur. Therefore, their guard would temporarily be dropped.
The other reason may be Battle of Badr, which was fought by Muhammad himself in the month of Ramadan. This may have considered by Arabs as a good precedent. (I am just speculating this, as the plan to attack Israel was code-named Operation Badr).
Ramadan fasting and Performances:
I tried lot for getting some authentic sources and information on this part of Yom Kippur war or Ramadan War, but yielded no positive results.
So, I am just drawing some conclusions, or you may called it speculations, based on the circumstantial evidences :