Yara Shahidi celebrating Yalda with his family in the U.S

Yaldā Night or Chelleh Night is a Northern Hemisphere’s winter solstice festival celebrated on the “longest and darkest night of the year.” According to the calendar, this corresponds to the night of December 20/21 in the Gregorian calendar, and to the night between the last day of the ninth month (Azar) and the first day of the tenth month civil calendar.