We believe all countries abide by the 12-month guideline. But Ethiopia is different: unbelievably, the African nation has a calendar with 13 months in a year.

The 12 months of the Ethiopian calendar have 30 days each, while Pagume, the final month, has five days on average and six on leap years. The name derives from the Greek term epagomene, which means “days forgotten when a year is calculated.” In the Ethiopian calendar, one year has 365 days, six hours, two minutes, and 24 seconds. Six hours sum up to 24 hours once every four years, which is the sixth day of a leap year. Every 600 years, two minutes and 24 seconds sum up to a full day. The Ethiopians refer to this seventh day as rena mealt and rena lelit. Given that 2014 began in September of last year, this means they are seven to eight years behind the rest of us. As a result, Ethiopians celebrate the start of a new year on September 11 or September 12 if it’s a leap year. Due to its unique calendar, the nation also observes a greater number of public holidays than other nations throughout the world.

The Gregorian calendar is generally known in Ethiopia, and some people even use both calendars interchangeably. Nevertheless, modern-day Ethiopia continues to use the traditional calendar. If you’re traveling to Ethiopia, be sure to check the dates!