Many people have lauded 2020 as the beginning of a new decade. However, history suggests otherwise.
According to Craig Callender, a professor of philosophy at UC San Diego, there is no “year zero” in our current calendar. Therefore, the only way to measure decades is to start them ending in one.
Introduced in 1582, the Gregorian calendar transitions from the years B.C.E. (Before Common Era) to the years labeled A.D. (Anno Domini or “Year of the Lord”). The B.C.E. years count down to 1 B.C.E, which is immediately followed by 1 A.D.
Given this information, the first A.D. decade began in year 1 and continued until the end of year 10; the second decade began in year 11. Hence, the new decennium should begin on January 1, 2021.
With this, one can say we are not living the dawn of a new decade, but the end of an old one.