the flag to fly on June 12

According to wiki:
The Philippine Declaration of Independence occurred on June 12, 1898 in the Philippines, where Filipino revolutionary forces under General Emilio Aguinaldo (later to become the Philippines' first Republican President) proclaimed the sovereignty and independence of the Philippine Islands from the colonial rule of Spain after the latter was defeated at the Battle of Manila Bay during the Spanish-American War.

The declaration, however, was not recognized by the United States or Spain, as the Spanish government ceded the Philippines to the United States in the 1898 Treaty of Paris, in consideration for an indemnity for Spanish expenses and assets lost.

The United States recognized Philippine independence on July 4, 1946 in the Treaty of Manila.[1] Independence Day was observed in the Philippines on the July 4 anniversary of this event until, upon the advice of historians and at the urging of nationalist politicians, President Diosdado Macapagal signed Republic Act No. 4166 into law on August 4, 1964, designating June 12, which had previously been observed as Flag Day, as the country's Independence Day.