The longest night of the year in the past 50 years

The longest and darkest night of the year marks “the night opening the initial forty-day period of the three-month winter”, from which the name Chelleh, “fortieth”, derives.There are all together three 40-day periods, one in summer, and two in winter. The two winter periods are known as the “great Chelleh” period (1 Day to 11 Bahman, 40 full days), followed/overlapped by the “small Chelleh” period (10 Bahman to 30 Bahman,[rs 2] 20 days + 20 nights = 40 nights and days). Shab-e Chelleh is the night opening the “big Chelleh” period, that is the night between the last day of autumn and the first day of winter. The other name of the festival, ‘Yaldā’, is ultimately borrowing from Syriac-speaking Christians.[rs 1][rs 3][rs 4] According to Dehkhoda,[rs 5] “Yalda is a Syriac word meaning birthday, and because people have adapted Yalda night with the nativity of Messiah, it’s called the name; however, the celebration of Christmas (Noël) established on December 25, is set as the birthday of Jesus.