Hearts of the World was created on 1918-01-01.
Kingdom Hearts was created to hold hearts of light and darkness so that a new world can be created, and whoever gets the hearts, designs the world. (As said in the secret reports in Kingdom Hearts Birth by Sleep)
From Their Hearts was created in 1998.
Thunder into Our Hearts was created in 1976.
A Gamble with Hearts was created in 1923.
The Five of Hearts was created in 1911.
Beating of Hearts was created in 1983.
Hearts Aflame was created in 1987.
Hearts Are Wild was created in 1992.
Hearts a Mess was created in 2007.
Changing Hearts was created in 1981.
Northern Hearts was created in 1947.
The Blue Hearts was created in 1985.