This Kurdish tradition is very similar to ancient Jewish traditions. According to the Jewish historian Josephus who lived in the first century, Israel had two New Years—the commercial New Year, which began in the fall of the seventh month, and the religious New Year, which started in the spring first month).

Newsal, Nusal or Nusar is translated into English as "new year." It comes from Nausardi or Nusardi ("new year") in Old Kurdish. In some regions, the festival also has local names, for example, Gaxn "Gakhan" in Dersim in northern Kurdistan, Cejna Xore "Feast of the Sun".

The earliest recorded date of Nusardi being celebrated by Kurds- along with Mehrakan, Tiriaski and Newroz, comes from the 3rd century CE. 

The festivities of Nûsal begin on December 21 and last until the first week of January. Some Xorkanî Reya Heqi/Kurdish Alevis, celebrate Gaxan on December 31. 

This festival is very similar to the Christian celebration of Christmas, and both are originally Mithraic traditions. This annual celebration on December 25 was the most crucial celebration of Mithraism, sun-worshipping; it was believed that Mithra was born on this day. 

Mithraism has been practiced in modern-day Kurdistan since the Mitannian period (1600 BCE). The non-Abrahamic Kurdish sects of Yarsanî, Yezidî/Ezidî, and Xorkanî/Rêya Heqî are regarded as the sole remnants of Mithraism in the region.

According to the beliefs of Kurdish religious sects, the world remains a permanent fixture of the cosmos, year in and year out. Each year, however, is ruled by a different "Padişa—King—of the turning time." Following summer solstice, as the days begin to grow shorter, the Padişa, likewise, becomes older. By the end of the year, they are ready to pass on their temporal kingdom to the next Padişa – which is a renewed, yet distinct, version of himself/herself, becoming younger as the days grow longer. 

On the last Thursday of December, just after the winter solstice, the festival of Newsal/Nûsal is held, ushering out the old year - and the old Padişa - and welcoming in the new Padişa.

Among northern Kurds, the festival's centerpiece is a procession called Khalkek, in which several people wear traditional costumes and parade around their town or village. One of the performers, representing the outgoing Padişa, wears a white beard and carries a cane or other accessories of old age. Another performer, representing the world itself, is made up as a beautiful woman. A third performer, representing the incoming Padişa, is dressed as a young person with a blackened face (dark cosmos) – it is said that their face is dark because their star has only just begun to rise in the inner, spiritual world. Its light cannot yet be cast into the outer world, which will have to wait until March when they claim his throne.

While musicians beat drums and play the zurnas (oboe-like wind instruments), these three characters, sometimes joined by others in traditional dress, go from door to door, house to house, shop to shop, collecting food and money.

Traditionally, all the food would be brought to the home of the poorest family in the village or neighbourhood, where a feast is prepared. A couple of hours before the party, right around sunset, prayer rituals are held at sacred places, such as hilltops and springs. Prayers are offered for the new year, and lokma – sacramental food, in this case, a buttery cake - is shared among the congregation. 

The idea behind the Newsal/Nûsal is to refresh oneself spiritually. According to this custom, "when the world was renewed, humans were renewed. As the world gets renewed humans too get renewed and rejuvenated. As the world gets old, humankind gets old. After we enter a new year, we are also becoming a new people."