Dia dos Namorados - June 12th

While a large part of the world celebrates Valentine's Day, there are some places where the day set aside for love is different.  In Brazil the day is known as Dia dos Namorados which means "Day of the Enamored".  In additions to many of the things one would expect for Valentines Day such as chocolates and flowers there are also parades and carnivals.  Women without someone are also known to preform certain rituals that are meant to add in them finding a boyfriend or husband.  The day following Dia dos Namorados is Saint Anthony's Day the saint of marriages which is where it is believed this celebration comes from.

Links:
Wiki: http://en.wikipedia.org/wiki/Valentine%27s_Day#Central_and_South_America

Other: http://traveler.fivestaralliance.com/index.php/2009/05/19/brazil-is-for-lovers-celebrating-dia-dos-namorados/