I got this message posted on my Facebook wall this week:
GOOD LUCK EVERYONE This year October has 5 Mondays, 5 Tuesdays and 5 Wednesdays. This happens once every 823 years. This is called Money Bags. So Share this at your wall and money will arrive within 4 days!
Reality is a bit more boring. Here's reality:
October 2012 is interesting because it has only 4 weekends, but it has 5 Mondays, Tuesdays and Wednesdays. Amazingly, this happens, on average, only once every seven years. It hasn't happened since 2007. It won't happen again until 2018.
Oh, and it's been 4 days, and the guy who posted it hasn't said anything about winning the lotto or anything, so I think it might not have worked.
You see, since October always has 31 days, and a week always has seven days, October will always have five Mondays, Tuesdays and Wednesday every time the month begins on a Monday. This year, October 1st fell on a Monday. This happens, on average, every seven years, not every 823 years. It doesn't happen every seven years evenly, howeve. Because of leap years, the pattern (except over the turn of each century that does not conclude a millenium) is for it to happen after 6, 5, 6 and 11 years. After 2018, it won't happen again until 2029.
You might enjoy the patterns that we saw in 2010 a little more. In 2010, the month begins on Friday, so October will have five Fridays, Saturdays and Sundays instead. Sadly, that pattern is on the 11 years now, so you won't see it again until 2021. Of course, if you like having all day to get ready for trick-or-treating, and you don't want the kids to have to do it on a school night, 2015 will be a great October. That one starts on a Thurday, which means Halloween is on Saturday. Call that month Candy Bags.