Who Created Calendar. In colder countries, the concept of the year was. Starting in 46 b.c., roman emperor julius caesar implemented the creation of a new calendar — the julian calendar.
When julius caesar introduced his calendar in 45 b.c.e., he made 1 january the start of the year, and it was always the date on which the solar number and the golden number were incremented. The calendar was created first by the mesopotamians, who lived in the fertile crescent formed by the tigris and euphrates rivers.