The calendar used by Islam is divided into solar calendar and lunar calendar. The solar calendar is used for farming, with 365 or 366 days a year, which is basically the same as the Gregorian calendar. The lunar calendar is used for religious affairs, with 354 or 355 days a year, which is always ten days different from the cycle of the four seasons. The second day after the Prophet Muhammad entered Medina (July 16, 622 AD) was the first day of the first year of the Islamic calendar. Eid al-Adha is a religious festival, which is on the tenth day of the twelfth month of the Islamic calendar; Eid al-Fitr is the second day after the end of Ramadan and seventy days before Eid al-Adha. Due to the difference between the dates of Eid al-Adha and Eid al-Fitr and the Gregorian calendar, these festivals are sometimes in winter and sometimes in summer. Different seasons have different colors of festivals, which makes the festivals unusually colorful. When Eid al-Adha is approaching, housewives in every household are busy. They have to make a lot of fried Sanzi and various exquisite snacks to prepare sufficient food for relatives, friends and guests from afar who come to their homes to celebrate during the festival. The grand festival is also a great display and competition of housewives' craftsmanship and housekeeping virtues. Eid al-Adha is Arabic, meaning "sacrifice" and "sacrifice", so Hui scholars translate Eid al-Adha as the Festival of Sacrifice, and some also translate it as the Festival of Loyalty and Filial Piety. The festival originated from an Islamic story: In order to test the loyalty of the prophet Ibrahim, God gave Ibrahim a dream at night and asked Ibrahim to slaughter his son as a sacrifice. Ibrahim did it without hesitation. When he was about to cut the throat of his biological son Ismail with a knife, God sent a messenger to replace Ismail with a black-headed sheep. Because of this origin, every Muslim household must slaughter at least one sheep during the Eid al-Adha, and some also slaughter cattle, camels, and horses (Sak and Kyrgyz). If the family is too poor, they must also slaughter a chicken. However, due to various restrictions, urban Muslims now have to buy slaughtered beef and mutton in the market. During the Eid al-Adha festival, everyone visits each other to celebrate the festival. Every time you visit a house, the host will serve a large piece of stewed mutton to the guests, and no matter how full the guests are, they must taste the mutton of the host. When relatives and friends gather together, the people of all ethnic groups in Xinjiang, who regard singing and dancing as their meals, will play the piano, sing songs, and dance, and there will be a happy scene everywhere. After the big gathering ceremony, every household will go to the cemetery to pray, remember and bless their deceased relatives. The morning prayer on the day of Eid al-Adha is the largest prayer of the year. All adult men have to go to the local mosque to participate in the gathering ceremony, and the scene is spectacular. The most famous one is the big gathering ceremony in front of the Id Kah Mosque in Kashgar. After the gathering ceremony, the musicians climbed onto the top of the door of the Id Kah Mosque, beat the nagla (iron shell drum) and played the sunaiyi (suona), and the men in the square in front of the mosque danced a passionate and unrestrained shaman dance. (No pictures available, please provide them.) (No pictures available, please provide them.)