Parents' Day is observed in South Korea and in the United States. The South Korean designation was established in 1973, replacing the Mother's Day previously marked on May 8, and includes public and private celebrations. The United States day was created in 1994 under President Bill Clinton. Parents' Day is observed in South Korea and in the United States. The South Korean designation was established in 1973, replacing the Mother's Day previously marked on May 8, and includes public and private celebrations. The United States day was created in 1994 under President Bill Clinton.