The Julian calendar was introduced by Julius Caesar in 46 BCE and was used in various parts of the world for centuries. It was based on a 365-day year with an extra day added every four years to account for the Earth’s orbit around the sun. However, this system eventually led to a discrepancy between the calendar year and the solar year, causing seasonal drift.
In the Julian calendar, leap years were determined by dividing the year by 4, resulting in a leap year every four years. While this system worked reasonably well for some time, it was not entirely accurate and required adjustments to keep the calendar in sync with the solar year.
Julian Calendar Vs Gregorian Calendar
The Gregorian Calendar
In 1582, Pope Gregory XIII introduced the Gregorian calendar to address the inaccuracies of the Julian calendar. The Gregorian calendar made several adjustments to the Julian calendar, including changing the rules for determining leap years. Under the Gregorian calendar, a year is a leap year if it is divisible by 4, except for years that are divisible by 100 but not by 400.
The Gregorian calendar also introduced a 10-day correction to bring the calendar back in line with the solar year. To implement this correction, days were skipped in October 1582, and the calendar was adjusted to ensure future accuracy.
Key Differences
One of the main differences between the Julian and Gregorian calendars is the method used to calculate leap years. The Gregorian calendar’s more complex system of leap years results in a closer approximation of the solar year, making it more accurate than the Julian calendar.
Another key difference is the adjustment made by the Gregorian calendar to correct the seasonal drift that had occurred under the Julian calendar. By skipping days in 1582 and refining the rules for leap years, the Gregorian calendar has remained the standard calendar used by most of the world today.