Answer:
The main reason why religious festivals are not celebrated on the same days every year is because they are calculated according to the lunar calendar called “kameri takvim”. Ramadan and the Feast of the Sacrifice are celebrated ten days earlier each year than the year before, so religious festivals may come to be celebrated in every season. According to the Kameri calendar, Ramadan is celebrated on the first three days of the month Sevval, and the Feast of the Sacrifice is celebrated in four days following the tenth day of the month Zilhicce. These festivals continue to exist in popular tradition, although their effects are not what they once were.
