1. Some Ethiopians use a 12-hour clock, with the hours cycling from 1 to 12 from dawn to dusk, and then from dusk to dawn. Unlike our way of calculating time, the start of the Ethiopian day is dawn, rather than midnight. So 7:00 AM would be 1:00 in Ethiopian time. 12:00 noon and 12:00 midnight are both 6:00, and 6:00 is 12:00.
2. The Ethiopian calendar, called the Ge’ez Calendar, is composed of 12 months plus five extra days that comprise a 13th month. Every four years, without exception, there is a 6th day in the extra month. This system is based on the Coptic or Alexandrian calendar, and the New Year begins the year on September 11th by our reckoning.