What happens every 823 years?
There is an internet hoax going around claiming that certain
occurrences of five days in a month occur every 823 years.
For examples, in October 2010, there were five Fridays,
Saturdays, and Sundays. However, this occurrence occurs at the most
every 11 years. The next time five Fridays, Saturdays, and Sundays
occurs in a month is March 2013. The next time it occurs in October
is October 2021.