Or, in this case, years. As a part of a previous post (found here) which has garnered some … interest … here’s a quick video on the different calendars we’ve had in the world. I’d explain here, but, just watch the video. Take note, in the video it’s explained that the Romans used to have an eight day week. So the Beatles weren’t that far off*.
And here’s another video explaining it all. Or, at least explaining how much bunk the 2012 Mayan calendar ending in 2012.
I hope this brings about some insight as to the different lines of thought on how days, weeks, years, months, so on and so forth have changed over the thousands of years.
*And now, the Beatles.