In the month of Dzulhijjah it is recommended for every Muslim to increase their worship. Apart from sacrificial worship, it is also recommended to fast sunnah in the month of Dzulhijjah. Dzulhijjah sunnah fasting starts on the 1st of Dzulhijjah to the ninth of Dzulhijjah.
Especially the eighth day is called the Tarwiyah fast and the ninth day is called the Arafah fast.