• Millennium
  • Century
    • Decade
      • Year
        • Month
          • Day
            • Hour
              • Minute
                • Second

As time goes forward, changes in periods of time cause changes down the hierarchical chain; an hour doesn’t change without a minute and second changing too, just as a year doesn’t change without a month, day, hour, minute, and second changing along with it.

When we talk about hours, we know that each hour is made up of 60 minutes— minute zero to minute 59. When the clock ticks and that 59 turns to 00, we’ve entered a new hour. Similarly, when 23:59 turns into 0:00, we’ve entered a new day. This works the same way all the way up the chain.

We’ve got no problem agreeing that one second after December 31st at 23:59:59 is January 1st of the following year—a new year. But somehow when we continue up the chain to decades and millennia people freak out and bring Jesus into the equation. Leave that guy out of this discussion.

Look at it this way. Each number in the year corresponds to a period of time. A change in each of the columns indicates a new period of time.

• Change in the ones column, i.e. 2008 -> 2009, indicates a new year.
• Change in the tens column. i.e. 2009 -> 2010, indicates a new decade, along with a new year.
• Change in the hundreds column. i.e. 1899 -> 1900, indicates a new century, along with a new decade, and year.
• Change in the thousands column. i.e. 1999 -> 2000, indicates a new millennium, along with a new century, decade, and year.

It’s a beautiful system. Trying to claim that the Aughts don’t end today, and the Tens don’t start tomorrow is preposterous, as is claiming the decade hasn’t ended yet. The numbers simply don’t back the claim. Today is the end of a decade, and tomorrow is the start of a new decade. Don’t let anyone tell you otherwise.