Islam celebrates a number of special occasions which are observed with devotion and joy to seek the pleasure of, and as a thanksgiving to, Allah. Islamic festivals are observed according to the Islamic calendar, which is based on lunar months. The lunar year is shorter than the solar year by about eleven days. Festival dates are determined by the phases of the moon. There are two major festive occasionsin islam in each year - Idul Fitr and Idul Adha.  
  

Idul Fitr 

Idul Fitr is observed at the end of Ramadan. Muslims express their joy and relief by offering a congregational prayer of gratitude to Alah for giving them their strength to fast for the whole month of Ramadan. The day is a rleigious holiday in Muslim countries. It is customary to visit friends and realtives, to give presents to children and to prepare special foods. Muslims generally wear their best or new clothes of Idul Fitr. The occasion is known as the time of zakat-al fitr, the time for the payment of zakat.  
 

Idul Adha  

Idul Adha begins on the tenth day of the month of Dhul-Hijja, and continues until the thirteenth day of the month. It commemorates the prophet Ibrahim's readiness to sacrifice his son Ismail on ALlah's command. ALlah accepted Ibrahim's devotion and obedience and, because of this, asked him to sacrifice a lamb instead. This occasion is observed by offering congregational as in Idul Fitr. Following the prayer, those Muslims who can afford to, sacrifice animals (sheep, cows or camels) and share the sacrificial meat among relatives, neighbours and the poor.  

Other occasions which are observed and celebrated include:  
 

• Lailatu Al Qadr (night of Destiny or Power) in Ramadan; 
• Lailatu Al Isra and Miraj, the night of Muhammad's journey to Jerusalem and ascent to Heaven as told in the Quran; 
• the beginning of Hijra; 
• the birthday of the Prophet Muhammad (s.a.w.).