May 15 is celebrated annually as the International Day of Families, proclaimed by the United Nations General Assembly, in its resolution 47/237 of 20 September 1993. This annual observance reflects the importance, which the international community attaches to families as well as its concern regarding their situation around the world. The International Day of Families provides an opportunity to promote awareness of issues relating to families as basic units of society as well as to promote appropriate action in support of their importance. 

Theme of the International Day of Families of the year 2007 is: "Families and Persons with Disabilities”

More about the International Day of Families:

http://www.un.org/esa/socdev/family/IntObs/IDF/IDFframe.htm