 Shab-e Chelleh is the night opening the "great Chelleh" period which falls between the last day of autumn and the first day of winter.The other name for the festival, 'Shab-e Yaldā', was borrowed from Syriac-speaking Christians..In the 1st–3rd centuries CE, large numbers of Eastern Christians settled in Arsacid and Sassanid territories, where they received protection from religious persecution.