With the change from the ‘Old’ to the ‘New’ Calendar after the 1917 Revolution, there was a difference of 12 days. However, modern Russian research not only adjusts the day of Stalin’s birth, but also sets it a year earlier. As far as I can tell, the ’21st’ date and the ’18th’ dates are matters of opinion rather than concrete facts. They are viewed as different versions of the facts. If the Baptism is correct, then he must have been born in 1878, etc. During the life of Stalin (and for a long time after his death), it was believed that he was born on December 9 (21), 1879, but later researchers established a different date for his birth – December 6 (18), 1878 – and the date of baptism 17 (29 ) December 1878.
The historian G.I. Chernyavsky writes that the name of Joseph Dzhugashvili appears in the registration book of the Assumption Cathedral in Gori and the following is written: “1878. Born on December 6th. He was baptized on December 17th. Parents – residents of the city of Gori, the peasant Vissarion Ivanov Dzhugashvili and his legal wife Ekaterina Georgievna. The Godfather is a resident of Gori, a peasant Tsikhatrishvili.” He concludes that the true date of Stalin’s birth is December 6 (18), 1878. It is noted that, according to the St. Petersburg Provincial Gendarme Administration, the date of birth of I.V. Dzhugashvili is December 6, 1878, and in the documents of the Baku Gendarme Administration the year of birth is marked 1880. At the same time, there are documents of the Police Department, where the year of birth of Joseph Dzhugashvili is marked as 1879 and 1881. The document – personally filled out by I.V. Stalin in December 1920, the questionnaire of the Swedish newspaper Folkets Dagblad Politiken – indicates the year of his birth as being ‘1878’.
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