Kandil (from Latin: candēla, "a candle") is one of the five Islamic holy nights when the minarets are illuminated and special prayers are made: Mevlit, Regaip, Miraç, Berat, Kadir.
The story of Kandil
The five holy evenings on the Muslim calendar are called Kandil. During the Ottoman Empire Sultan Selim II of 16th century lit candles on the minarets of the mosques in order to announce these holy nights to the public. Since this calendar is calculated with the revolution of the moon around the earth the dates of the Kandils differ every year.
References
Kandil Wikipedia(Text) CC BY-SA