[LINK] The Albert, Bernard, and Cheryl birthday question

[Andy Farkas]

Colleagues of mine on IRC stumbled upon this (apparently 5th grade!) 
question:

%%%
24. Albert and Bernard just become friends with Cheryl, and they want to 
know
when her birthday is. Cheryl gives them a list of 10 possible dates:

    May 15   May 16       May 19
   June 17  June 18
   July 14  July 16
August 14  August 15  August 17

Cheryl then tells Albert and Bernard separately the month and the day of her
birthday respectively.

Albert:  I don't know when Cheryl's birthday is, but I know that Bernard
          does not know too.

Bernard: At first I don't know when Cheryl's birthday is, but I know now.

Albert:  Then I also know when Cheryl's birthday is.

So when is Cheryl's birthday?
%%%


No cheating by looking up the answer!

-andyf