Yalda
In Iran, before the rise of Islam, there was a religion called Zoroastrianism that included a holiday known as Yalda. Yalda, also referred to as Chelleh, marked the anniversary of the birth of Mithra, the goddess of light, and celebrates the sunrise after the longest night of the year.
Ancient Persians believed that evil forces were strongest on the longest and darkest night of the year. People stayed up all night, telling stories and eating watermelon and pomegranate, in addition to dried fruit, in anticipation of the sun rising.
As the light spilled through the sky in the moment of dawn, Persians celebrated its appearance with drumming and dancing. It was thought that the day after the longest night belonged to Ahura Mazda, the Zoroastrian lord of wisdom.
source: Britannica.com