Ramadan ( ; also spelled Ramazan, Ramzan, Ramadhan or Ramathan) is the ninth month of the Islamic calendar, observed by Muslims worldwide as a month of fasting (sawm), prayer, reflection and community. A commemoration of Muhammad's first revelation, the annual observance of Ramadan is regarded as one of the Five Pillars of Islam and lasts twenty-nine to thirty days, from one sighting of the crescent moon to the next. Fasting from dawn to sunset is fard (obligatory) for all adult Muslims who are not acutely or chronically ill, travelling, elderly, breastfeeding, diabetic, or menstruating. The predawn meal is referred to as suhur, and the nightly feast that breaks the fast is called iftar. Although fatwas have been issued declaring that Muslims who live in regions with a midnight sun or polar night should follow the timetable of Mecca, it is common practice to follow the timetable of the closest country in which night can be distinguished from day. The spiritual rewards (thawab) of fasting are believed to be multiplied during Ramadan. Accordingly, during the hours of fasting Muslims refrain not only from food and drink, but also tobacco products, sexual relations, and sinful behavior, devoting themselves instead to salat (prayer) and study of the Quran. Etymology The word Ramadan derives from the Arabic root R-M-Ḍ () "scorching heat", which is the Classical Arabic verb "ramiḍa ()" meaning "become intensely hot – become burning; become scorching; be blazing; be glowing". Ramadan is thought as one of the names of God in Islam by some, and as such it is reported in many hadiths that it is prohibited to say only "Ramadan" in reference to the calendar month and that it is necessary to say "month of Ramadan", as reported in Sunni, Shia and Zaydi sources. In the Persian language, the Arabic letter (Ḍād) is pronounced as /z/. The Muslim communities in some countries with historical Persian influence, such as Azerbaijan, Iran, India, Pakistan and Turkey, use the word Ramazan or Ramzan. The word Romzan is used in Bangladesh. History Muslims hold that all scripture was revealed during Ramadan, the scrolls of Abraham, Torah, Psalms, Gospel, and Quran having been handed down on the first, sixth, twelfth, thirteenth (in some sources, eighteenth) and twenty-fourth Ramadans, respectively. Muhammed is said to have received his first quranic revelation on Laylat al-Qadr, one of five odd-numbered nights that fall during the last ten days of