Day of the Victims of the Occupation of Czechoslovakia in Slovakia is observed on August 21st. This day serves as a somber reminder of the military invasion by Warsaw Pact countries including the Soviet Union, East Germany, Poland, Hungary and Bulgaria in 1968. This invasion put an end to a period known as "Prague Spring," which was marked by a series of liberal reforms aimed at modernizing Czechoslovakia's political, economic and social structures.

The day is marked with various activities such as laying wreaths at memorials to honor those who lost their lives during the occupation, public speeches by political figures, screening documentaries about the event or hosting exhibitions showcasing pictures and other artifacts from that era. There are also various discussions and debates held about the historical significance of the occupation.

In recent years, there have been efforts to educate younger generations about this dark chapter in Slovakia's history through programs in schools and public forums. The day serves not only as a remembrance for those who suffered but also as an opportunity for reflection on values such as freedom, democracy, and human rights.

The Day of Victims of Occupation does not involve any specific traditions or customs. It is primarily seen as a day for solemn reflection rather than celebration.