Julian calendar irregular years, this extra-long year was, and is, referred to as the "last year of confusion". The new calendar began operation after the realignment had been completed, in 45 BC. The Julian months were formed by adding ten days to a regular pre-Julian Roman year of 355 days, creating a regular Julian year of 365 days. Two extra days were added to January, Sextilis (August) and December, and one extra day was added to April, June, September and November. February was not changed in ordinary years, and so continued to be the traditional 28 days. Thus, the ordinary (i.e., non-leap
Decimal calendar Decimal calendar A decimal calendar is a calendar which includes units of time based on the decimal system. The original Roman calendar consisted of ten months (however, the calendar year only lasted 304 days, with 61 days during winter not assigned to any month). The months of Ianuarius and Februarius were added to the calendar by Numa Pompilius in 700 BC. The ancient Egyptian calendar consisted of twelve months, each divided into three weeks of ten days, with five intercalary days. The French Republican Calendar was introduced (along with decimal time) in 1793, and was similar to the ancient Egyptian