Each year, Muslims spend the ninth month of the Islamic calendar observing a community-wide fast. Muslims who are physically able are required to fast each day of the entire month, from sunrise to sunset. The evenings are spent with family and community meals, engaging in prayer and spiritual reflection, and reading from the Qu'ran.

Muslims all over the world abstain from food, drink, and other physical needs during the daylight hours. Ramadan is much more than just not eating and drinking.

Ramadan also was a pagan month in Arabia. In pre-Islamic times, Ramadan became a pagan Arabian ritual and was practiced by the pagan Arabians with the same features as the Islamic Ramadan.

Fasting was an important practice for the Arabians, It was practiced by the tribes of Medina Oas and Khazraj,before Mohammed came to them. 

In the pre-Islamic Jahiliyah they fasted that month in the same way Muslims fasted, as originally directed by Mohammed. Pagan Arabian abstain from food , water, and sexual contact the same as practiced by Islam.

 Mohammed  Kept these this rituals of fasting Ramadan as an Islamic pillar, see the Five Pillars of Islam .

Mohammed added his rituals to that pagan month to fit the religious rituals and customs of Oas and Khazraj, the two tribes from al-Medina.