Who Invented The Calendar Of 365 Days. It was more accurate than the previously used roman. Based on the julian calendar, there were 365.25 days in a year.
In contrast, the mayans of central america relied not only on the sun and moon, but also. Julius caesar is credited with changing the roman calendar from 355 days to 365 days and for adding leap year days every few years (and for changing the name of quintilis to.