# Do you think the decade ends 12-31-09?

Asked by simpleD (3644) December 15th, 2009

Here we go again. Folks are making their “best of the decade” lists. But I say the tenth year of the decade completes 12–31-10. We’ve heard the arguments starting in 1999. Let’s have it again, here. Do you think a new decade begins or ends on the multiples of 10? In other words, do you count the year following the birth of Christ as year 0 or year 1?

Observing members: 0 Composing members: 0

Millennium was 31–12-99.
Century was 31–12-99.

Do you really think the decade started 01–01-01?

delta214 (744)

20th Century was 1901–2000
21st Century started 2001–2100
End of the millenium was in 2000.

However, the decade is actually 2000–2009, 2010–2019, e.g., the 80’s wasn’t 1981–1990.

And, for the record, I researched it in 2000. Nobody was confused in 1900/1901 about the new century being Jan 1, 1901 and not Jan 1, 1900. I blame Prince.

grumpyfish (6618)

What? Of course 2009 is the end of the decade. Are you serious?

No way, Jose. It begins on the 0. From the beginning of 2000 to the end of 2000 is one year. The end of 2000 is the beginning of 2001. So from the beginning of 2000 to the beginning of 2001 is one year. That means that from the beginning of 2000 until the beginning of 2002 is two years. That means that from the beginning of 2000 until the beginning of 2010 is ten years, or a decade. And since the beginning of 2010 is the same as the end of 2009, the decade ends this year.

jfos (7362)

It is is it is conceived which is that it ends 12–31-09.

marinelife (62234)

Yes, it’s the end of the decade. And there is no year 0. Has never been. Year 1 was calculated somewhere in the 4th century, and is supposed to be from conception.

Jacket (665)

The first year is a zeroth year. Therefore, the tenth year always ends with nine.

robmandu (21252)

I agree with @grumpyfish. You didn’t count the year 2000 as part of the 90’s. So hello new decade!

ShiningToast (2101)

@Jacket I’m talking about a theoretical 0, stronso.

jfos (7362)

@jfos I wasn’t referring to you. But I guess you like calling people a piece of shit just for giggles.

Jacket (665)

Unfortunately, this ultimately comes down to semantics.

To @Jacket‘s point, the Gregorian calendar (used by most countries today) has no year zero. But I argue that point is meaningless in today’s vernacular.

When people refer to the decade of the nineties, they will always mean the years 1990–1999. The year 2000 is not part of the nineties.

robmandu (21252)

@robmandu Yep!

The 90’s, the 2000’s, the 1900’s are different divisions than centuries and millenia.

TECHNICALLY there is a thing called a “Decade” (e.g., the 1st decade was years 1–100, the 200th was 1991–2000), but we don’t use those in common vernacular.

E.g., nobody is saying “the 10 greatest songs of the 201st Decade”

grumpyfish (6618)

@Jacket Not for giggles. I had a flash of passion. My apologies.

jfos (7362)

Okay, so we have the common vernacular: a decade is a group of years sharing the number in the 10s place. But we also have mathematical accuracy: The first of anything cannot be counted as zero, so the first decade was 01–01-01 through 12–31-10. So we can proceed understanding that the decade is over, even though only 2009 can’t be divided evenly by 10.

simpleD (3644)

@simpleD says, “The first of anything cannot be counted as zero.”

In programming, the first array index is typically a zero.

And besides, if we’re talking mathematical accuracy, zero is a real number after all.

robmandu (21252)

this thread is why I love Fluther

gemiwing (14708)

@robmandu: I stand corrected. I should’t have overgeneralized. But I think “numbering” and “counting” are two different processes.

simpleD (3644)

For me, it ends 12/31/09. To me, the end of the second millennium and the 20th century was 12/31/99. Wikipedia will disagree with me, but whatever.

DominicX (28762)

@simpleD I accept that that this isn’t the end of the 210th Decade, but that’s a bit of a mouthful.

grumpyfish (6618)

When you count from 1 to 10, you don’t have ten until you get to 10. I have to use all ten of those digits to count my fingers. I’m not on somebody else’s hand until I get to 11.

Jeruba (47530)

I think about it like the first second of a stopwatch: The first second is at time zero (0:00.000–0:00.999); the second second begins at 0:01–0:01.999 and so on, so the tenth second spans 0:09.000–0:09.999, and so the “eleventh” second begins at 0:10.

The same can be said for counting in years, even though there was no “zero” year, the reason was that the counting system was switched over after that first year retroactively. But if somehow there had magically been a consensus for that counting system at the time of Christ’s conception, the clock would have started at time zero (0:00 or zero hour or 12:00am) on January 1st, 0000. So, if we’re still counting on a base 10, then the decades end at 12:00am going from the 9th to the 10th-numbered year.

So I cast my vote for decade ending this NYE.

sndfreQ (11724)

No. I just think all the hype was invented by the marketers of the movie!

Theby (998)

@sndfreQ: You almost convinced me with the clock starting at 00:00. Still, though, there are only 24 hours in a day. We don’t count each hour from 0–24, because that would give us 25 hours. The first hour completes as 00:59 ends. The 24th hour completes as 23:59 ends. So, the first decade completed as 12–31-09 ended.

simpleD (3644)

Wouldn’t you know…fouled out by a technicality!!! Short story long, we have another year left in the “Ott Decade.” 2010 is the last year of this current decade!

When the Julian and Gregorian calendars were adopted (different times mind you), it was decided that there technically was no “Year Zero,” so that retroactively, the year dating went from “1BC” on the last day of that year, to “1 AD” the next day.

So by that standard, the year 1AD is the “first year” of the first century, the year 100 is the last year of the first century. And the same would go for decades, even though there is a 0 in 2000 or 2010, those are the 10th years of each decade, respectively.

That’s why the news media kept reporting that on New Year’s 1999, that technically, we still have one more year in the decade/millennium, but that for marketing (and Prince’s) sake, the celebration started a year earlier on NYE ‘99—‘00.

sndfreQ (11724)

So @sndfreQ, you’ve reversed your previous position? Your last post clinches it, and reaffirms my thoughts exactly.

simpleD (3644)

@simpleD It was a valiant effort, but we all make mistakes…I guess it was only a half-baked theory at best I’m afraid. The hours still count that way though!!

Damn you Julius Caesar, you foiled my diabolical plan to rule the world again, but you also make a mean salad, so, it’s a wash! Now I’m hungry…Pavlov, get my coat, we’re going out for breakfast!

sndfreQ (11724)

@sndfreQ The “Aught Decade” ends this year—same as the 80’s, 90’s, etc.. The 201st decade ends at the end of 2010.

It’s all a question of what you’re talking about.

grumpyfish (6618)

@grumpyfish perhaps I “aught” not continue misinforming on this thread!!!

sndfreQ (11724)

Nah, it was all a good read. Interesting thread and good discussion.

Jacket (665)

@sndfreQ Ha! =)

grumpyfish (6618)

In grade school we got our knuckles rapped, figuratively or literally, if we had said, for example, that Lincoln was an 18th century figure based on his having lived and died in the 1800’s. 1900 ended the 19th century and, yes, 1990 was part of the 1980’s.