To be fair to the original poster, September 8th is also a reference to the date: 9-8-2009, which many find scary.
To some people, if you add up those numbers you get 27. Add 27 together and you get 9. Divide 9 by 3 and you get 3. Multiple 3 by 2 and you get 6. Triple 6 and you get 666, or the mark of the Anti-Christ. Hence, keep your child home from school because the Anti-Christ will be serving lunch that day.