Which South Park episode aired 29 days before the day that "everybody" was asked to draw Mohammad?
Everybody Draw Mohammed Day:  A drawing representing Mohammed was posted on the Internet on April 20, 2010 with a message suggesting that "everybody" create a drawing depicting Mohammad on May 20 in support of free speech. 201 (South Park):  It originally aired on Comedy Central in the United States on April 21, 2010.
201