Yaldā Night or Chelle Night is an ancient festival in Homeland, Iraqi Kurdistan, Afghanistan, Azerbaijan, Tajikistan, Uzbekistan, Turkmenistan, and Turkey that is celebrated on the winter solstice.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 (Dey) of the Iranian solar calendar.