### Monday, Monday...

Pi Day falls on a Monday this year.  But you knew that by now, since the Doomsday for 2011 is Monday. This means that, in 2011, the following dates are all Mondays:

• 4/4

• 6/6

• 8/8

• 10/10

• 12/12

Think "I work 9 to 5 at the 7-11" and you'll remember these Mondays:

• 9/5

• 7/11

...and their opposites:

• 5/9

• 11/7

There's Pi Day (or Einstein's birthday, if you prefer), the Fourth of July, Halloween, and the day after Christmas:

• 3/14

• 7/4

• 10/31

• 12/26

So if someone asks, "What day of the week is September 20," you think, "I know the 5th is a Monday, so the 12th and the 19th are Mondays... Tuesday."

Of course you'll need a nice pi shirt for Pi Day.  Here's a cool one:

And here are a couple other math shirts from Woot.  I got the counting sheep.  Number 3 is pooping.