An End Of The Year Message From J. Michael Persnickety.
Despite what you may have read, said, seen on T.V., heard on the Radio, or believed this is not the end of a decade. The decade began in January 2011 and will end in December 2020. Think about it. We count from 1-10, not from 0-9. The Gregorian Calendar (Pope Gregory XIII) was introduced in 1587. It revised the Julian Calendar (Julius Caesar 45 BC), a noble work which had small errors in the calculation of the Earth's annual journey around the Sun. The Gregorian calendar ( now the international calendar for trade, diplomacy and travel) corrected most of the errors of the Julian. Pope Gregory, for good or for ill, decided that the first year of Our Lord (the birth of Jesus) would be A.D. 1 ; prior years were designated B.C, (before Christ). Thus the first decade, in the Calendar we all use, began in January A.D. 1, and ended in A.D. 10. So it is that our current decade began in J...