Perhaps, not many who know that, today, 16th of September is Malaysia Day, the day Malaysia was formed. The Malaysia day is very significant although it's not really well known as compared to the Merdeka Day.
Malaysia day is the day to commemorate the formation of the establishment Malaysian Federation on 16th of September 1963. On this day, Malaya, North Borneo (now Sabah), Sarawak, and Singapore
(Singapore left Malaysia in 9th of August 1965 to form a new state) joined together to form Malaysia. From this day onwards, Malaya was known as Malaysia.
At first, the formation of Malaysia was arranged to be on 1st of June 1963 but was later postponed to 31st of August 1963 so that it would coincide with the 6th Merdeka Day. Because of the objection from the Indonesian and Filipino towards the formation of Malaysia, this was further postponed to 16th of September the same year. The postponement to 16th was also to allow the United Nations (UN) to conduct the referendums in North Borneo and Sarawak regarding the 2 states participation in the Federation of Malaysia.
The current map of Malaysia
The formation of Malaysia, however were opposed by Indonesia strongly and lead to "Ganyang Malaysia" campaign by the president then, Sukarno and this is the start of Indonesia-Malaysia Confrontation (Konfrontasi) (1963-1966). This confrontation ended when General Suharto seized the power from Sukarno.
Ganyang MAlaysia campaign by Sukarno
trivia:
1)The change of the name from Malaya to Malaysia by adding additional "si" to the middle of Malaya was believed to be due to the new states (Sabah, Sarawak and Singapore) start with letter "s" while Singapore start with letter "si" hence we get Malay-si-a
2) Due to the formation of Malaysia, there had been changes made to the the original flag of the FederationMalaya with 11 red and white stripes and 11-pointed star ( which represent 11 states of the Malaya) by adding 3