Shab-e Yaldā or Shab-e Chelleh is an Iranian festival originally celebrated on the Northern Hemisphere’s longest night of the year, that is, on the eve of the Winter Solstice.

The 13th century Iranian poet Sa’di wrote in his Bustan: “The true morning will not come, until the Yalda Night is gone”. Following the Iranian calendar reform of 1925, which pegged some seasonal events to specific days of the calendar, Yalda came to be celebrated on the night before and including the first day of the tenth month (Dey). Subject to seasonal drift, this day may sometimes fall a day before or a day after the actual Winter Solstice

Following the fall of the Sassanid Empire and the subsequent rise of Islam, the religious significance of the event was lost, and like other Zoroastrian festivals Yalda became a social occasion when family and close friends would get together. Nonetheless, the obligatory serving of fresh fruit during mid-winter is reminiscent of the ancient customs of invoking the divinities to request protection of the winter crop