The Calendar Year 2010 - When the Decade Ends
It is New Year's Eve, 2009.
I've been online reading about the new decade which begins, in the estimation of some, tomorrow; the first day of 2010.
While this may sound good, and the beginnings and ends to things are always news-worthy milestones, as a mathematician I feel it is my duty to straighten out this misnomer.
Or, perhaps I should say mis-number.
In reality, the first decade of the Twenty-First century ends when the year 2010 ends.
The second decade of the Twenty-First century begins at the instant the year 2011 begins.
While I know it is confusing to think of the number 10 the same way we think of single digit numbers like 7, 8, and 9, all these numbers are actually contained in the same group which is known as a decade.
The Year 0? Go to your favorite search engine and type in "the year 0.
" You will find there was no such year.
The first year after 1BC was 1AD.
So, obviously, the first decade or ten years AD included the year 10.
This means, of course, 1950 was in the 40's and 1990 was in the 80's and 2010 is part of the first decade of the 21st century.
So there, it didn't take long to convince you, now did it? What, you're still confused? Okay.
A man who is 35 years old, like me, (a-hem) is in his 36th year.
So, it follows on his next birthday he will be 36.
At the same instant he turns 36 years old he will begin his 37th year.
This is because we don't celebrate our first birthday until our first year has ended.
When we are born we are 0 years old.
So, we complete our first decade of life as soon as we are no longer 9 years old.
As we turn 10, or when we are no longer 9, we enter into our 11th year and at the same time, our 2nd decade.
He's 2010 Years Old Today! So we humans have a year 0.
However, the Julian and Gregorian calendars, the two main calendars of history, do not.
So, when I become 2010 years old, it will be in my 2011th year of life.
The year 2010 however, is in the 2010th year of the calendar.
Once you realize there was no year 0 and the word decade literally means group of 10, you can't fall for the false notion that the current decade we are living in has just ended with the year 2009.
The only way you could think this decade ended New Year's night, the minute following 11:59 PM, 2009 is to believe some decade along the way consisted of only 9 years.
Maybe you think that decade was the first decade.
Whatever decade you think was 9 years long would have to be the decade that didn't have 10 years and that would be the same as saying it was the decade that wasn't a decade! Calling things other than what they are works in philosophy, politics and some dubious scientific so-called consensuses, like global warming, but it doesn't work in mathematics.
Mathematics has rules that must be followed and one such rule is the one that states a decade is ten years long! So, there you have it.
1950 was indeed, part of the 40's.
1990 was part of the 80's.
The year 2000 was part of the 90's and the third millennium didn't begin until the year 2000 ended because the year 2000 was one of the first 2000 years AD.
So, the third millennium began as the year 2001 began.
If you don't believe it, just do an online search for "the third millennium starts.
" In any event, have a happy New Year but not a happy new decade yet.
Not unless, you're reading this after the year 2011 has started.
I've been online reading about the new decade which begins, in the estimation of some, tomorrow; the first day of 2010.
While this may sound good, and the beginnings and ends to things are always news-worthy milestones, as a mathematician I feel it is my duty to straighten out this misnomer.
Or, perhaps I should say mis-number.
In reality, the first decade of the Twenty-First century ends when the year 2010 ends.
The second decade of the Twenty-First century begins at the instant the year 2011 begins.
While I know it is confusing to think of the number 10 the same way we think of single digit numbers like 7, 8, and 9, all these numbers are actually contained in the same group which is known as a decade.
The Year 0? Go to your favorite search engine and type in "the year 0.
" You will find there was no such year.
The first year after 1BC was 1AD.
So, obviously, the first decade or ten years AD included the year 10.
This means, of course, 1950 was in the 40's and 1990 was in the 80's and 2010 is part of the first decade of the 21st century.
So there, it didn't take long to convince you, now did it? What, you're still confused? Okay.
A man who is 35 years old, like me, (a-hem) is in his 36th year.
So, it follows on his next birthday he will be 36.
At the same instant he turns 36 years old he will begin his 37th year.
This is because we don't celebrate our first birthday until our first year has ended.
When we are born we are 0 years old.
So, we complete our first decade of life as soon as we are no longer 9 years old.
As we turn 10, or when we are no longer 9, we enter into our 11th year and at the same time, our 2nd decade.
He's 2010 Years Old Today! So we humans have a year 0.
However, the Julian and Gregorian calendars, the two main calendars of history, do not.
So, when I become 2010 years old, it will be in my 2011th year of life.
The year 2010 however, is in the 2010th year of the calendar.
Once you realize there was no year 0 and the word decade literally means group of 10, you can't fall for the false notion that the current decade we are living in has just ended with the year 2009.
The only way you could think this decade ended New Year's night, the minute following 11:59 PM, 2009 is to believe some decade along the way consisted of only 9 years.
Maybe you think that decade was the first decade.
Whatever decade you think was 9 years long would have to be the decade that didn't have 10 years and that would be the same as saying it was the decade that wasn't a decade! Calling things other than what they are works in philosophy, politics and some dubious scientific so-called consensuses, like global warming, but it doesn't work in mathematics.
Mathematics has rules that must be followed and one such rule is the one that states a decade is ten years long! So, there you have it.
1950 was indeed, part of the 40's.
1990 was part of the 80's.
The year 2000 was part of the 90's and the third millennium didn't begin until the year 2000 ended because the year 2000 was one of the first 2000 years AD.
So, the third millennium began as the year 2001 began.
If you don't believe it, just do an online search for "the third millennium starts.
" In any event, have a happy New Year but not a happy new decade yet.
Not unless, you're reading this after the year 2011 has started.
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