Here’s a post for the penultimate day of 2019. Tomorrow is 2020 and the start of a new decade. Or is it? There is real disagreement on when a new decade begins.
Some people say that the new decade “officially” begins with years ending in 0 while others say a new decade begins in years ending in 1. Is there a correct answer? Generally, people would say that the decade of the 90s began in 1990, 1890 et al.
You can also consider when centuries and millennia begin in the same way. The official answer on that is that the 21st century and the third millennium began on New Year’s Day 2001. That’s because in our modern anno domini time reckoning system there is no year zero. Year 1 BC was followed by year AD 1. But there was certainly much celebration for the new millennium on January 1, 2000.
With decades, it’s more about language than about calendars. Unlike centuries, we would never say “the 200th decade” to mean the next decade. (Technically, the upcoming decade is the 203rd decade. but I am not getting into that.) Chances are we will call this next decade “the twenties” though that might confuse it with the 1920s (the “roaring twenties”).
It will be widely accepted that the new decade will begin when the ball falls at midnight on January 1, 2020, but you can legitimately celebrate again a year later.
If you say to me that something happened in “the 90s” I assume you mean the 1990s and not 1890s. But what do you call that time from 2000-2009? In North America, the term “the aughts” was used (but not by me) and other English speaking countries used “the noughts” or “the noughties.”
And the 2010 -2019 has been referred to as “the teens,” “the teenies,” “the teensies” and “the tens.” I don’t like any of those names. I would probably opt for “the twenty-tens” (“the 2010s”) but my browser’s spell-grammar checker and Grammarly app doesn’t seem to like any of those. Did we go through ten years and we still haven’t decided what to call it? I suppose this decade that is ending will be named in hindsight. Happy 2020, readers!