The Islamic calendar, Muslim calendar or Hijri calendar is a lunar calendar consisting of 12 lunar months in a year of 354 or 355 days.

Being a purely lunar calendar, it is not synchronized with the seasons. With an annual drift of 10 or 11 days, the seasonal relation repeats about every 33 Islamic years.

It is used to date events in many Muslim countries (concurrently with the Gregorian calendar), and used by Muslims everywhere to determine the proper days on which to observe the annual fast (see Ramadan) and to attend Hajj, in addition to celebrate other Islamic holidays and festivals.

The first year was the Islamic year beginning in 622 CE during which the emigration of Muhammad from Mecca to Medina, known as the Hijra, occurred. Each numbered year is designated either H for Hijra or AH for the Latin anno Hegirae (in the year of the Hijra), hence, Muslims typically call their calendar the Hijri calendar.

The current Islamic year is 1433 AH, from approximately 26 November 2011 (evening) to 14 November 2012 (evening).

Abu Ameenah Bilal Philips (born Dennis Bradley Philips on 6 January 1946 in Jamaica) is a contemporary Islamic scholar, teacher, speaker, and author, resident in Qatar. He appears on Peace TV, which is a 24-hour Islamic satellite TV channel broadcasting to many countries around the world.

Philips was born on 6 January 1946 in Jamaica, but grew up in Canada, where he converted to Islam in 1972. He received his B.A. degree from the Islamic University of Medina and his M.A. in Aqeedah (Islamic Theology) from the King Saud University in Riyadh, then to the University of Wales, where he completed a PhD in Islamic Theology in the early 1990s. Philips comes from a family of educators, as both his parents were teachers and his grandfather was a Christian minister and Bible scholar.

In 1994 he founded (and continues to direct) an Islamic Information Center, now known as Discover Islam, in Dubai, United Arab Emirates.

The Islamic Online University has been founded by Dr. Bilal Philips as a completely tuition-free institution that is offering an online intensive, undergraduate, and graduate courses in Islamic Studies. The university offers a four year bachelor of arts degree in Islamic studies program.

Zakir Abdul Karim Naik (Urdu: ذاکر عبدالکریم نائیک; born 18 October 1965) is an Indian public speaker on the subject of Islam and comparative religion. He is the founder and president of the Islamic Research Foundation (IRF), a non-profit organisation that owns the Peace TV channel based in Dubai, UAE. He is sometimes referred to as a televangelist. Before becoming a public speaker, he trained as a doctor. He has written two booklets on Islam and comparative religion. He is regarded as an exponent of the Salafi ideology; he places a strong emphasis on individual scholarship and the rejection of "blind Taqlid", which has led him to repudiate the relevance of sectarian or Madh'hab designations, all the while reaffirming their importance.

Zakir Abdul Karim Naik was born on 18 October 1965 in Mumbai, India. He attended St. Peter's High School in Mumbai. Later he enrolled at Kishinchand Chellaram College, before studying medicine at Topiwala National Medical College and Nair Hospital and later the University of Mumbai, where he obtained a Bachelor of Medicine and Surgery (MBBS). His wife, Farhat Naik, works for the women's section of the IRF.