Many people just won't get this, but then so many people are dickheads. It's really quite simple. Today is the first day of the new decade. I'm not going to repeat myself because you can jolly well read what I posted a year ago here. It's maths and in maths you have two choices, the right answer and the wrong answer. If you can't grasp this very simple concept about when decades start then you really are utterly stupid. If you start wittering on about Gregorian and Julian calendars then you are beyond stupid and need to crawl under the nearest stone. This is not up for discussion. You're welcome.