Happy New Year. From where I sit, January 1, 2020 looks an awful lot like December 31, 2019, which isn’t surprising. New Year’s Day is more of a time to change calendars than anything else. People used to be more superstitious about it, with a whole list of dos and don’ts. New Year’s Resolutions go back at least to the Babylonians, who probably kept them about as well as folks do now.

There’s some buzz about it being the beginning of a new decade, except it isn’t. Yes, I’m one of those who say the new decade doesn’t start until 2021. Of all the issues out there, the question of when centuries and decades start has to be near the bottom of the list. Maybe that’s why All Things Considered treated it like a fluff piece yesterday (although with the current state of journalism, it’s hard to tell). The topic of how we reckon years went from Anno Urbis Conditae or AUC, which dated years from the founding of Rome, to Dionysius Exiguus and our current Anno Domini. There was no mention at all of counting years from the start of the reign of Diocletian (given the state of journalism, that isn’t surprising), even though that explains a great deal about how we currently count years. For while counting years from the founding of Rome may have been popular in the western Roman Empire, counting years from when Diocletian became Emperor of the Roman Empire was the preferred reckoning in the eastern part.

Now, the thing you need to know about Diocletian is that he persecuted Christians. His effort to stamp out Christianity was known as the Great Persecution, and was marked by the wholesale slaughter of Christians. For that reason, The Diocletian Era is sometimes called the Era of Martyrs.

This brings us to Dionysius Exiguus. He was a monk who lived in the Eastern Roman Empire in the 5^th and into the 6^th Centuries. As was common for that place and time, years were counted from when Diocletian became emperor. One fine day, as Dionysius was working on a table of dates for Easter, he was struck that using years reckoned from when a murderer of Christians became emperor was seriously uncool. Easter is a Christian observance, so what would be more appropriate than using years reckoned from the birth of Jesus Christ? Dionysius estimated a year for Jesus’ birth, and used that instead. He started noting dates in both in the year of the reign of the current consul, and by his new reckoning system.

What does his have to do with whether 2020 is the start or end of a decade? Plenty. To understand what was going on, let’s look at reckoning years from when Diocletian became emperor. From that point until the first anniversary of his reign, events could be said to take place during the first year of the reign of Emperor Diocletian. “During” is the key word here. From the moment he became emperor until the first anniversary of the event, his first year of reign was unfolding. On the date of the first anniversary, he started his second year of reign, and so on.

You can apply the same thing to your own life. If you are, say, twenty years old, you have lived twenty years, and are working on your twenty-first.

The thing to keep in mind about all this is that there is no year zero with this type of reckoning. Remember, before you were a year old, you were living out the first year of your life. This means that on your tenth birthday, you had lived ten years, but you were in your eleventh year of life. So the year 2020 AD means that we are in the two thousandth and twentieth Year of our Lord. If Dionysius was correct in his calculations, this past Christmas would have been the two thousandth and nineteenth anniversary of the birth of Jesus Christ.

All this means is the year 2020 marks the end of the two hundredth and second decade of the Year of our Lord. A new decade won’t begin until January 1, 2021.

That’s not a popular way of looking at it, and there were howls of protest when I pointed that out to family yesterday. But by the way Dionysius reckoned years, the next decade doesn’t start until 2021. So here’s wishing you that the last year of the second decade of the 21^st Century will be happy one. And may the start of the third decade next year be even better.