Originating in Japan, the 3rd day of the 3rd month has been dubbed Hina Matsuri or more commonly known as Girl's Day. Celebrated in Japan it is also celebrated by many cultures in other countries (e.g.: Hawaii. Traditionally, families with daughters set up a doll display in their home of either a single female doll and/or a male and female doll together. They also offer rice crackers and perhaps small trinkets while they pray for the good health and happiness of their daughters.
It's mostly a day that parents get their daughter a small gift or take her for a treat. It's also a day when mother's spend extra quality time with their daughters.
[Boy's Day is May 5th (05/05)!]