It was made a national holiday by government decree in 1946.
Ceremonies and festivities are held throughout the country to celebrate this national day, including the flag hoisting ceremony conducted nation-wide and at Indonesian diplomatic installations abroad, local community competitions, with patriotic and cultural parades. On 16 August, the President of Indonesia addresses the nation at the People’s Consultative Assembly.
On 17 August, at 10.00 AM Western Indonesian Time all Indonesian national television stations broadcast the National Independence Day Ceremony live from the Merdeka Palace in Jakarta. And earlier at 7 AM local time, cities and regencies throughout Indonesia conduct the flag hoisting ceremony at their respective city halls. Streets, public places and public transportation are filled with nationalistic and patriotic decorations and art dominating with the red and white color symbolizing the national flag of Indonesia throughout the month of August.
According to Wikipedia
