Bollocks
You can start a decade any time you like.

1st January 2001 - 31st December 2010? That's a decade.

1st January 2000 - 31st December 2009? That's a decade too.

14th July 1997 - 13th July 2007? So's that.

Exactly the same goes for millennia. 1st January 1000 - 31st December 1999 was the millennium in which the four digit year started with a 1. A far more sensible definition than "One to two thousand years from the estimated and up to 30 years out birth date of a prophet", frankly.

And ... relax.

Incidentally, why do none of the anal retentive millennium definers ever take account of the calendar shift half way through? They should have held their self-righteous parties on the night of January 13th/14th 2001 ...
(ubergeekian, Fri 1 Jan 2010, 17:25, 1 reply)

Calendar alterations are irrelevant
The Romans used to start the year on the first (well, kalends if we're being picky) of March, then changed their minds later. We used to start it on 25 March (Lady Day - nine months before the supposed birth of Christ), which is why the tax year still starts on 6 April (when we switched to the Julian calendar, the tax man didn't want to lose 13 days' revenue).

However, a millennium is a thousand complete years, no matter how short or long some of those years happen to be, and since that monk bloke who came up with the current system decided it would start in AD 1 (the first year of Our Lord), the current millennium therefore began in 2001.

The "Noughties" were still 2000-2009 though. :o)
(Vice Admiral Sir Charles Cockbrush KCB MBE DSO, who is finding it increasingly difficult to log into b3ta.com wants to duck your aunt and kick your puppy, Sun 3 Jan 2010, 9:11, closed)