The article is devoted to a historical chronological calendar problem of the middle of the 19th century was the time of frequent chronological discussions that deterred the further evolution of Russian chronological science. The author pay special attention to Khavsky Peter Vasylievich (1774-1876), who had taken part in discussing and tried to sound his own point of view on all the most important historical chronological problems. It was P.V. Khavsky who had declared for the first time there were two different calendars starting in March. The first starting in March calendar forestalled the calendar starting in September. The time of forestalling was 6 months. The second starting in March calendar was 6 months slow than the starting in September calendar. The idea was not taken into consideration in the middle of the 19th century because there was another old Russia chronology realization by Tatizhev and Karamzin. However, the idea declared by N.V. Stepanov was recognized to be a scientific discovery in the 2

0th century.