WASHINGTON (AP) _ President Clinton's declaration that Tuesday's speech was the last State of the Union address of the 20th century sounded logical, but wasn't quite correct.

In fact, next year's State of the Union speech, in January 2000, will be the last of this century.

When the current Gregorian calendar was devised in the sixth century by a monk named Dionysius Exiguus, counting was done using Roman numerals, which do not include a zero.

So he called the first year ``I'' and counted from there.

That results in a century running from 1 through 100 and the next from 101 through 200, a millennium from 1 through 1000 and the next from 1001 through 2000, and so forth.

Thus, 2000 _ not 1999 _ is the last year of the 20th century and 2001 will be the first year of the 21st century.