Ramadan, also spelt Ramadhan, marks the ninth month of the Islamic Calendar, with the first and last dates determined by the lunar calendar and the appearance of the crescent moon, or Hilāl, and commemorates Muhammad's first revelation. Ramadan is marked for twenty-nine to thirty days, from one Hilāl to the next, with adult Muslims participating in fasting (fard) from dawn to sunset during the month, as well as abstaining from other behaviours to devote themselves to prayer (salat) and study of the Quran. The predawn meal (suhur) and the nightly feast (iftar) are notable even among non-Muslims, as iftar meals have become a means of sharing with friends, neighbours, coworkers and the community during this time.
Ramadan contains celebrations for Laylat al-Qadr, the holiest night of the year taking place during Ramadan, and ends with Eid al-Fitr, which marks the first day of Shawwal (the new month).
Ramadan begins 10 to 12 days earlier each year, making it so that in 2030, Ramadan will actually be celebrated twice in one year.