One of the major objectives of the French Revolution was to switch all measures of time from base 12 to base 10, including a ten day week. Ironically, the experiment lasted 12 years.
It is 2006 in Ethiopia because their calendar has 13 months. The 13th month is only 5-6 days long and the reason it’s 2006 rather than 2014 is because it’s based on the Coptic calendar rather than the Gregorian.
Ethiopia has 13 months, is still in the year 2005, and celebrates New Years on September 11.