In 49B.C. Julius Caesar ordered the Roman calendar to be improved. The new calendar was based on a solar year of 365 1/4 days and began in January (Januarius) to coincide with the terms of politicians that began in January. A leap day was added in February, every fourth year. 90 days were added to the year causing the spring to begin in March.
The Romans developed a calendar based on the solar year. They chose the month of March as their first month. The year had 305 days and consisted of 30 and 31 days.