Into a new decade
Only a few days left of this year. After that we will be entering into a new decade: twenties. Or are we?
Some people thing the decade doesn't start until the year one e.g. this decade started in 2011 and will last until the end of year 2020. Mathematically that makes sense. The way we count from one and up to ten. There also wasn't year zero in Anno Domini era, so strictly speaking this interpretation is also true if we just count all the ten years along the way. Otherwise counting decades wouldn't add up to a current year.