MILLENNIUM FEVER BROKE at the beginning of this year, but the sickness lingers among some tortured souls who believe that the third millennium (in the Christian world) doesn't really start until about now.

Tom Danehy makes that claim in his column this week, and our chroniclers of Y2K's dubious achievements (beginning on page 16) are willing to write off the dismal year 2000 and start fresh.

The calendar problem originated with the early monks who figured the Christian dating system. They were ignorant of the number zero, and that has thrown everything off to this day (unless you join me in declaring that the first century A.D. had only 99 years, thereby allowing every century thereafter to start with a double-zero year, as it should).

But this whole millennium thing is irrelevant, anyway. Two thousand years since what? Jesus seems to have had his roll in the manger's hay in 6 B.C. The Jewish calendar turned its first page in 3761 B.C. The Muslim era began in 622 A.D., with Muhammad's emigration from Mecca.

Eras rarely begin in double-zero years. Culturally, the 1960s began with Kennedy's 1963 assassination and ended with Nixon's 1974 resignation. The 19th century really began around 1789 with the French Revolution and the flowering of Romanticism, and ended in 1914, when the seeds sown through Europe by the French Revolution brought the body harvest of World War I.

The 20th century may have ended in 1989, with the fall of communism in Europe, or in 1995, with the advent of widespread access to the Internet. Or maybe the century's (and millennium's) true end is yet to come. At any rate, the sanest course may be to follow AA's directive: Take one day at a time.