National Day is one of twelve public holidays in Belgium. It's annually observed on July 21 to celebrate the day, when Leopold of Saxe-Cobourg swore allegiance to the new Belgian constitution and became the first King of Belgium.
Health Care and Medical Industry Worker's Day is a professional holiday, that is observed in Turkmenistan on July 21. This holiday brings together all health experts regardless their specific field of activity.
The mass race riots, that occurred in Singapore in 1964, became the basis for creation of Racial Harmony Day. This holiday is celebrated in Singapore on July 21 to commemorate the innocent victims of the riots.