The question is again pressing upon us:

IS 2020 THE START OF A NEW DECADE?

This question comes up repeatedly. It makes readily appreciable sense to account a new decade as starting with the rollover of the new digits — we easily know that 2020 is a clear division in our counting scheme, so it is sensible that it should serve as the boundary for a new decade. Yet the very most insistent amongst us insist that, No! A decade starts on the xx01 year following xx00. Of course, since there was no Year Zero, it is true, from a purely mathematical perspective, that the first “decade” would have been from Year One to Year Ten, inclusive, because a decade is, strictly speaking, ten years.

But a “decade” is also a generalized term of calendration, much as a month, a year, or a century is. Yet we have absolutely no problem with irregular months, or variable years, or inconsistent centuries, so it seems rather strange to insist upon rigid consistency with decades.

Since long before Julius Caesar declared, upon extensive consultation and coordinations with his Greco-Egyptian astronomer Sosigenes, that 45 BC (“Annus Confusionis“) should last a rather astonishing 445 days, irregular calendration had been pragmatically used from time to time to resolve issues with the calendar. Add to this fact that Caesar promulgated the insertion of a quadrennial “Leap Day” to correct the calendar so that every fourth February is an extra day longer. But, because Sosigenes’ every-four-year correction proved a bit too aggressive, Pope Gregory XIII acceded to the omission of nine days to reset the calendar in 1582 to align with celestial mechanics (and when England finally got on board in 1752, 11 days were excised.)

Along with the skipping of days, the “Gregorian” calendar changed such that only centuries divisible by 400 would be leap years thereafter. (In 1600 and 2000 February had 29 days, but in 1700, 1800, and 1900, February had its usual 28 days.) These extra-calendrical solutions are purely pragmatic rather than algorithmic. They definitely mar the “purity” of the calendar, but they work! This sort of practical fudging is still done periodically today: “leap seconds” are from time to time inserted into the scheme of things these days. So there is no reason to insist that decades logically have to start on years one. Simply no reason. One cannot cite calendrical consistency, nor mathematical purity, to back up such an insistance. It is literally without precedence.

The reality is that decades pragmatically run from 0 – 9 because that is the way people treat them. It is plainly practical. A calendrical genius noted back in the late 1990s that the matter is actually readily resolved with a simple bit of pragmatic reasoning, one which noted essayist Stephen Jay Gould concurred with: The first “decade” of the current era simply had nine years; the rest are correctly aligned 🙂 This simple, pragmatic resolution makes all of the debate moot.

This next New Year, 2020, is clearly the start of the newest decade. Anything else is an excess of pedantry.

THE CALENDAR IS HERE TO SERVE HUMANKIND,
NOT HUMANKIND TO SERVE THE CALENDAR.