1000 years means December 31, 2000, not 1999

This was the biggest plot hole in the entire movie. According to the film, Satan is supposed to be released at the end of every 1000 years, to attempt to impregnate a chosen woman. But there was no year zero!

There was 1 BC, which was immediately followed by AD 1. AD 1 was the first year of the first millennium, which ran from January 1, AD 1, to December 31, AD 1000.

January 1, AD 1001 began the first year of the second millennium. This means that the second millennium ended on December 31, 2000, so Satan would have been released at the end of the year 2000, not 1999!

This film was set one year too early, because the makers of the film and society at the time had no understanding of history or mathematics. I remember the end of 1999, when everybody was going crazy about the end of the millennium because they were too stupid to understand that the transition from 1999 to 2000 meant nothing.

The transition from 2000 to 2001 was significant, but nobody gave a ****.