Solar Calendar System Julian Calendar https://en.wikipedia.org/w/index.php?title=Julian_calendar&oldid=1063127575 https://www.commoncoreontologies.org/InformationEntityOntology A Solar Calendar System that has a regular Year of 365 24-Hour Days divided into 12 Months with a leap day added at the end of February every 4 Years such that the average length of a Julian Year is 365.25 Days. The Julian Calendar was proposed by Julius Caesar as a reform of the Roman Calendar, took effect on 1 January 46 BC, and was the predominant Calendar System in Europe until being largely replaced by the Gregorian Calendar.