The Federation of Malaya gained independence (Merdeka) from British rule on August 31, 1957. The official Malayan Declaration of Independence was read at 9:30 a.m. at the Stadium Merdeka in Kuala Lumpur, over 20,000 people gathered to celebrate the sovereignty of our country.
On August 30, 1957, the night before the official declaration, a crowd gathered at Merdeka Square — a large field in Kuala Lumpur — to witness the birth of an independent nation. The lights were turned off at 11:58 p.m. for two minutes of darkness. The British Union Jack was lowered, and Malaysia's new flag was raised in its place. At midnight, the lights were switched back on for the first time in the new country.
Sources: https://en.wikipedia.org/wiki/Independence_Day_(Malaysia)