This year, July has 5 Fridays, 5 Saturdays and 5 Sundays. This happens
once every 823 years.
First, July 2012 staarts on Sunday, so it has 4 Fridays, 4 Saturdays, 5 Sundays, 5 Mondays, and 5 Tuesdays.
Second, this last happened in 2007.
Third, the calendar has a 28 year cycle, so that this year the calendar is the same as it was 28 years ago and will be in 28 years. (This rule does have discontinuities around 1900, 2100, etc.) So I am always amazed when anyone says "This happens once every 823 years."
nacl