Technically, January 1st, 2020 is not the end of the decade

Photo credit (Getty Images / Sergey Peterman)

By Lindsey Peterson , 830 WCCO

As we steam towards New Year's Eve, many around the globe are preparing to celebrate the end of another decade.

There's only one problem. Technically, it's not the end of the decade.

Here's why: 2,019 years and 1 day ago, the date was not 12/31/00. It was 12/31/01.

If that seems illogical to you, don't feel like you're alone. From a cultural standpoint, it makes sense to celebrate a decade when we flip from 9 to 0 on the calendar. Earlier this December, a survey by YouGov.com found that 64% of adults believe the new decade begins this Wednesday. Only 17% believe it will start January 1st, 2021 while 19% say they're not sure.

From a technical perspective, we're a year away however.

The Farmer's Almanac agrees that 2021 is the start of the next decade. We'll quote them here:
"As you think about New Year’s resolutions, here’s one we should all make together: resolve to insist that decades begin with the year ending in the numeral 1 and finish with a 0. For a decade to begin, we must start with the year ending with 1 (2021) and finish with 10, or so far as chronology is concerned, a year ending in 0 (2030)."

They go on to explain the origins of why we start with year 1, blaming (if you will) someone named Dionysius Exiguus who was a monk born in Romania in the year 470. He was the first to suggest counting the passage of years from the date of birth of Jesus Christ, beginning the period of anno Domini or A.D. According to current-era scholars, many of the historians of that era got that start date wrong, but that's a different story.

When Dionysius finished his work, he calculated that 1 A.D. was immediately preceded not by a 0, but by 1 B.C. Which means decades actually being with a 1, as would a millenium. We celebrated the start of a new millenium on January 1st, 2000, but we were off by a year according to the actual calendar.

Think about it another way. Count to 10. Where did you start and finish?

As we look back from a cultural perspective, it's reasonable to say the 2010's end on 12/31/19. But from a mathematical or calendar perspective, we have a full year to go!