The Julian calendar was introduced by Julius Caesar in 46 BC and was in use until the 16th century. It was based on a 365-day year with an extra day added every four years to account for the extra quarter day in the solar year. This system, known as the leap year, worked fairly well but over time it began to drift out of sync with the actual solar year.
In the Julian calendar, the year began on March 25th and had 12 months, with alternating 30 and 31 days except for February, which had 28 days in a common year and 29 days in a leap year. This calendar was used throughout the Roman Empire and beyond until it was replaced by the Gregorian calendar.
Gregorian Calendar Vs Julian
The Gregorian Calendar
The Gregorian calendar was introduced by Pope Gregory XIII in 1582 as a reform of the Julian calendar. It was designed to correct the errors that had accumulated in the Julian calendar over the centuries and bring the calendar back in line with the solar year. The main change was the adjustment of the leap year rule to exclude years ending in “00” unless they are divisible by 400.
The Gregorian calendar also changed the start of the year to January 1st and introduced a more accurate system for calculating leap years. This calendar is now the most widely used calendar in the world and is the standard calendar for most countries and international organizations.
Key Differences
One of the main differences between the Gregorian and Julian calendars is the leap year rule. While the Julian calendar adds a leap day every four years, the Gregorian calendar excludes certain years from being leap years to better align with the solar year.
Another key difference is the start of the year. The Julian calendar began the year on March 25th, while the Gregorian calendar starts the year on January 1st. This change was made to bring the calendar in line with the winter solstice and the start of the new year in many cultures.