Resumo
The chronological systems used by the first chroniclers are very poorly understood. The purpose of the article is to propose a new method that will clarify our understanding of the chronographic (annual) dates given in The Tale of Bygone Years. The article proposes to use information about indirect manifestations of solar activity to identify texts that precede The Tale of Bygone Years. This made it possible to identify several reports of the Tale of Bygone Years, the annual dates of which are given according to the Annian era, which was 5500 years from the Creation of the world BC. A hypothesis that in one of the sources used by the compiler of The Tale of Bygone Years, annual dates are given in the Annian era, was proposed on this basis.