Ramadan is the ninth month of the Islamic lunar calendar, and lasts either 29 or 30 days, depending on when the new crescent moon is, or should be, visible.
The Arabic term Ramadan connotes intense heat. It seems that in pre-Islamic Arabia, Ramadan was the name of a scorching hot summer month. In the Islamic calendar, however, the timing of Ramadan varies from year to year. This year  Ramadan begins in most places on April 13. An Islamic year is roughly 11 days shorter than a Gregorian year.
What is the significance of Ramadan?
Ramadan is a period of fasting and spiritual growth, and is one of the five “pillars of Islam.” The others being the declaration of faith, daily prayer, alms-giving, and the pilgrimage to Mecca. Able-bodied Muslims are expected to abstain from eating, drinking and sexual relations from dawn to sunset each day of the month. Many practicing Muslims also perform additional prayers, especially at night, and attempt to recite the entire Qur’an. The prevailing belief among Muslims is that it was in the final 10 nights of Ramadan that the Qur’an was first revealed to the Prophet Muhammad.