Quantcast
When Does the New Decade Start? | Almanac.com

Order Your Almanac Today!

When Does the New Decade Start?

Photo Credit
Pixabay

Is 2021 the Start of a New Decade?

Catherine Boeckmann
December 30, 2020
Print Friendly and PDF

Is the year 2021 the start of a new decade? Or, did it begin in 2020; after all, we’re living in the “twenties.” It’s a simple question, but the answer can depend on the words you use! There are two ways of thinking about this. We’ll explain—and let us know what you think. 

What Is a Decade?

When does the new decade begin and end, anyway? Let’s consider what the word “decade” means. The Oxford Dictionary states, “a period of 10 years, especially a period such as 1910–1919 or 1990–1999.” That’s it.

Note how the dictionary references two decades, both starting in a year that ends in a “0” and ending in a year that ends in a “9.” We do commonly refer to “the 1990s” or “the nineties.” We don’t think of a decade as ending in “1” or as the “ninety-ones.”

Read Next

However, what may confuse people is that “century” and “millennium” do not follow this rule. Let’s take a century which is a period of 100 years. Based on Anno domini, the year numbering system we use today, the 21st century started on January 1, 2001. In this case, the year ends in a “1.”

Why? Based on our numbering system, Anno domini, there is no year zero. The year 1 BC was not followed by 0, but rather by year AD 1, so we count up from the year 1 AD as in the “21st century.”

Notice that we don’t speak the same way when it comes to decades. Even though the 2020s will be the 203rd decade, we don’t call it that. We call it the “2020s.”

So, Is 2021 the Start of a New Decade?

There is some debate about whether the “new decade” began on January 1, 2020, or will begin on January 1, 2021. To put it plainly: Does the decade begin with a year ending in “0” or a year ending in “1”?

Well, it depends on the context:

  1. Culturally, we say “the eighties” or “the twenties.” In other words, people commonly think of a decade (such as the 1980s, 1990s) as years ending in 0 to years ending in 9. So, 2010 to 2019; 2020 to 2029.  
     
  2. However, today’s Gregorian calendar counts decades starting with the first year 1 CE. As discussed above, the Gregorian calendar goes from 1 BCE to 1 CE; there is no year zero. In this case, 2021 is technically the start of the new decade.  

Our conclusion? It simply depends on the context of what you’re saying. If you’re referring to ’80s music, we get it. If you’re the US Naval Observatory—in charge of the master clock—the new millennium began on January 1, 2001. 

At the end of the day, astronomy rules the day, and calendars are imperfect. An almanac, by definition, is a “calendar of the heavens.” The Earth will continue to revolve around the Sun, cycling through the seasons.

However you define a decade, let’s just celebrate the start of a new year—especially after 2020—and welcome new beginnings with the year 2021!!

Happy New Year!

Calendar

More Like This

2023 Almanac Club

Comments

Ridvan (not verified)

11 months ago

okay first of all y'all don't even know how to count you go from 0 to 1 and that's one same with the first year as well it starts with zero then 24 hours pass it becomes a day then 6 months pass it becomes half a year another becomes one but the entire year counts as one and a decade doesn't mean add it means a whole group of ten it's like saying a year is adding one year so essentially a year doesn't pass on year 1 it passes in year 2 with that logic we call it 1 year because it's a whole group of 1 year duh a group of ten is a decade a group of 100 is a century etc basically learn to count

Marcus Malik (not verified)

2 years 4 months ago

Referring to centuries by cardinal numbers, we have "the 1900s" (1900-1999), "the 2000s" (2000-2099), etc.

Referring to centuries by ordinal numbers, we have "the 20th century" (1901-2000), "the 21st century" (2001-2100), etc.

Referring to decades by cardinal numbers, we have "the 2010s" (2010-2019), "the 2020s" (2020-2029), etc.

Referring to decades by ordinal numbers, we would theoretically have "the 202nd decade (2011-2020), "the 203rd decade (2021-2030), etc.

Notice that one of these is not like the others. We "would theoretically" refer to decades that way using ordinal numbers -- except that *nobody actually does that*.

Decades are 0 to 9. Q.E.D.

Carol Shriner (not verified)

2 years 5 months ago

a decade started at the '0', especially after experiencing the dreaded turn of the century just 21 years ago...remember Y2K? But I do understand our number system as well. For example, our ages. If someone is born on April 2, 1960, their first birthday is held on April 2, 1961. On that date, they're actually starting to live in their SECOND year, not their first year, since they just lived through their first year. I actually try not to think about it too much or it'll blow my mind! ;c)