Do we start at “0” or “1”?

“Marine Bob” is a listener who emails me just about every day. He’s conservative and a Vietnam veteran who lost an eye there fifty years ago. He pumps iron every day, has a wide variety of knowledge and interests and can pass for younger than his actual age. Last week he wrote me with a question:

Chris, My wife and I were having the debate on whether the year 2020 is the end of the decade, or the start of a new decade. My wife is an electrical engineer and a lot smarter than me (Although my friends always tell me ‘but she married you, so it is questionable’). She thinks the year 2020 is the end of the decade. I think it is the beginning of a new decade. I am a logical person, so I will state my case thusly: When a person is born, they are on the clock. On their 10th birthday, on THAT day they have lived a complete decade, and although they are still called 10 that entire year, they are on to their 2nd decade. So too is the calendar. Even though it is 2020, we are on our way to 2021, which would be the 1st entire year of the new decade. What say you?
Bob

I thought about it for a bit. This was my answer:

On the calendar, there was no year O. The year the Pope decided to make a cornerstone between the old and the new was the year 1AD (anno domini, or the year of our Lord). The previous year was 1BC (before Christ, on the assumption that Christ’s birth occurred in the year 1AD. Since we count our age by the number of years passed (anniversaries) and not the year of our existence, Christ turned 10 in 11AD. According to the calendar, the first decade AD was 1 through 10, meaning that New Year’s Day in 11AD marked the beginning of the second decade. The second century AD began in 101, and the second millennium AD began in 1001.

Now on to the world of advertising. The gay 90’s, the roaring 20’s and the fabulous 50’s are all decades that lasted 1890-1899, 1920-1929 and 1950-1959. In sports, if you ask, “Who were the greatest players of the 1970’s”, you’ll get a list of statistics from 1970-1979, not from 1971-1980. The 1990’s ended on December 31, 1999, but the 21st century didn’t begin until a year later, on January 1, 2001. The 1900’s also ended December 31, 1999, but the 20th century didn’t. So when we talk about ages, anniversaries, decades, millennia and the like, we’re really having two different discussions. Your first year of life was “year one” for you, but your age was not 1 until you finished it.

I argued with the Boise Hawks and the Idaho Stampede (although not very hard) about these things in the past. The Hawks started in 1987, and in 1996 they printed their literature with “1996, our tenth anniversary season”. I told them the wording was wrong. Although 1996 was their tenth season, their tenth anniversary season wouldn’t be until 1997. which would be their 11th season. They told me “nobody cares”. And by that, they meant nobody except people like us.

Incidentally, when I was about 12 I asked my grandparents to answer the question, “If a baseball player played from 1970 to 1980, how many seasons did he play?” My grandma said 10. My granddad said 11. My grandma was mad when I told my granddad he was right. My mom told me to stop causing trouble. I never did stop, but I considered it.

Also incidentally, one of my favorite quotes is from Andre Maurois, who said, “In literature, as in love, we are astonished at what is chosen by others.”