The basis of Sadie Hawkins Day is that women and girls take the
initiative in inviting the man or boy of their dreams out on a 
date, to a dance attended by other single men and their 
liberated dates. Although in the original cartoon Sadie got 
herself a husband out of the deal! 

Al Capp the inventer of Li'l Abner was the one that first 
started Sadie Hawkins day way back on November 15th, of 1937.

While researching this famous "holiday" I've found some
 
conflicting information.  Though most agree that the "real" 
Sadie Hawkins day is in November (the first Saturday) there 
are some that says it is February 29th.  Though on this date
it's suppose to be okay for a gal to ask her fella to marry her..

All you need do to send a card is either click on the link below 
the image or the image itself.