On the date-of-the-millennium question, the late Steven Jay Gould related an interesting story.

He discussed the issue with a savant, who could barely tie his shoelaces but was a whiz at dates -- telling you the day of the week for an arbitrary date in the year 8726, and the like.

Gould asked this fellow when the 21st century started. He answered without hesitation, "January 1st, 2000. The first century only had 99 years."

Not definitive, of course, but it's an interesting perspective!