The Ethiopian Leap Year
A leap year in the Ethiopian calendar occurs every 4 years when an extra day is added to the last month of the year.
Adds Leap Day
The Ethiopian calendar consists of 13 months, where the first 12 months have 30 days each. The 13th month has 5 days in a common year and 6 days in a leap year.
It is a solar calendar, based on the solar (tropical) year. The Ethiopian calendar's historical roots are the same calculations that lie behind today's Gregorian calendar and its predecessor, the Julian calendar.
Why Add Leap Years?
Leap years are needed to keep the calendar in alignment with Earth's revolutions around the Sun.
It takes Earth approximately 365 days, 5 hours, 48 minutes, and 45 seconds (365.242189 days) to circle once around the Sun. This is called a tropical year (solar year) which is usually measured from one March equinox to the next.
Every 4 Years Is Too Often
Like in the Julian calendar, a leap year in the Ethiopian calendar happens every 4 years without exception. However, this is too often compared to the length of a solar year
Because if this, both the Julian and the Ethiopian calendar are several days out of sync with the fixed dates for astronomical seasons such as equinoxes and solstices. This is the reason why the Gregorian calendar eventually replaced the Julian system to become the world's standard civil calendar.
Gregorian Leap Years More Accurate
In the Gregorian calendar, 3 criteria work together to identify leap years:
- The year can be evenly divided by 4;
- If the year can be evenly divided by 100, it is NOT a leap year, unless;
- The year is also evenly divisible by 400. Then it is a leap year.
The more advanced leap year formula makes the Gregorian calendar far more accurate than the Ethiopian calendar. However, it is not perfect either. Compared to the tropical year, it is off by 1 day every 3236 years.
- Gregorian Calendar
- Julian Calendar
- Revised Julian Calendar
- Persian Calendar
- Mayan Calendar
- Chinese Calendar
- Roman Calendar
- Ethiopian Calendar
- Switch from Julian to Gregorian
- Is There a Perfect Calendar?
- What Do CE and BCE Mean?