People shop for Yalda Night at an old bazaar in Tonekabon, Iran, Dec. 21, 2019. Yalda Night is celebrated on the longest night of a year, which is locally believed to be on Dec. 21, the eve of winter solstice. (Photo by Ahmad Halabisaz/Xinhua)

People shop for Yalda Night at an old bazaar in Tonekabon, Iran, Dec. 21, 2019. Yalda Night is celebrated on the longest night of a year, which is locally believed to be on Dec. 21, the eve of winter solstice. (Photo by Ahmad Halabisaz/Xinhua)

People shop for Yalda Night at an old bazaar in Tonekabon, Iran, Dec. 21, 2019. Yalda Night is celebrated on the longest night of a year, which is locally believed to be on Dec. 21, the eve of winter solstice. (Photo by Ahmad Halabisaz/Xinhua)

People buy nuts for Yalda Night at an old bazaar in Tonekabon, Iran, Dec. 21, 2019. Yalda Night is celebrated on the longest night of a year, which is locally believed to be on Dec. 21, the eve of winter solstice. (Photo by Ahmad Halabisaz/Xinhua)