Who Used The Julian Calendar. From the early 18th century, since the time of peter the great, the country exclusively used the julian calendar, introduced in europe by julius caesar. It was based on the roman calendar and introduced by julius caesar in 46 bc.

Julian calendar, dating system established by julius caesar as a reform of the roman republican calendar. The majority of the orthodox churches worldwide use the julian calendar, created under the reign of julius caesar in 45 bc, and have not adopted the gregorian calendar,.