Ramadan is the holiest month in the Islamic calendar (Credit: Sanimdesigns/ CC-BY-SA-2.0/ Pixabay)

Ramadan is the ninth and most sacred month in the Islamic lunar calendar. During this month, Jibril (the archangel Gabriel in the Judeo-Christian faith) revealed the first verses of the Quran — Islam's holy text — to Prophet Muhammad. The holy month's start is based on the appearance of the young crescent Moon. This year, Ramadan will begin at sundown on March 22nd or 23rd, depending on when the Moon is seen.