Ramadan is observed by fasting.
Ramadan . also romanized as Ramazan , Ramadhan , or Ramathan ) is the ninth month of the Islamic calendar , and is observed by Muslims worldwide as a month of fasting ( Sawm ) to commemorate the first revelation of the Quran to Muhammad according to Islamic belief . While fasting from dawn until sunset , Muslims refrain from consuming food , drinking liquids , smoking , and engaging in sexual relations . Muslims are also instructed to refrain from sinful behavior that may negate the reward of fasting , such as false speech ( insulting , backbiting , cursing , lying , etc. ) and fighting except in self-defense .