February 9 – Thirty Comelec computer technicians walk out of their tabulation center at the PICC to protest attempts to manipulate the election results.[1]
February 16 – Cojuangco–Aquino leads Tagumpay ng Bayan (Victory of the People) rally in Luneta Grandstand with over 2 million attendees; proclaims victory in spite of the previous proclamation.[1]
February 24 – People Power Revolution (Day 3): Reformist rebels storm government offices, radio and television stations, Camp Aguinaldo, Villamor Airbase, and Malacañang Palace; 15th Air Force Strike Wing, with Col. Antonio Sotelo, defects to the rebels; Col. Mariano Santiago leads the soldiers who take over government-owned Channel 4.[1]
Marcos also swears in as President of the Philippines at Malacañang Palace; his own inauguration ceremonies are interrupted as other television stations are destroyed by rebels.[1][2]
March 25 – Pres. Aquino abolishes the national assembly and the constitution; declares an interim constitution (Freedom Constitution, Proclamation No. 3) effective until a new one would be ratified in a national plebiscite.[2]
July 4 – Street clashes in an anti-nuclear rally outside the US Embassy injure 14 policemen and six demonstrators.[2]
July 6 – Former Vice Pres. Arturo Tolentino, with Marcos loyalists and more than 300 soldiers, takes over the Manila Hotel; proclaims himself as "acting president"; Tolentino leaves the hotel and begins surrender talks on the 7th; they are forced to surrender peacefully after the failure of the coup that lasted until the 8th. Col. Rolando Abadilla would be identified as the mastermind.[2][3][4][5][9]
July 9 – Pres. Aquino prohibits rallies by Marcos supporters.[2]
September 5 – Pres. Aquino and Misuari, in Jolo, agree for negotiations aimed at ending a 14-year conflict.[2]
September 12 – The Supreme Court orders a retrial for former military chief Gen. Fabian Ver, 24 other military men, and a civilian, all acquitted in 1985 regarding their involvement in the 1983 murder of Benigno Aquino Jr. and Rolando Galman, as recommended on July 31 by a commission appointed by the Supreme Court.[2]
September 13 – The Mt. Data Peace Accord was signed between the Philippine Government and the separatist Cordillera Bodong Administration-Cordillera People's Liberation Army.[10]
September 14 – ABS-CBN went back on the air once again as it began rebroadcast to viewers and for station ID, the network carries the first tagline Watch Us Do It Again! followed by the second tagline Sharing A New Life with You. It features the first channel 2 logo is a wing-shaped blue crest with a white curved at the top and a white line as a tail, the Broadway 2 logo was used until 1987.
October 20 – Milk Code of 1986 (Executive Order No. 51) is signed by Aquino in order to implement rules and regulations in the manufacture of infant formula products.
November
November 11 and 22 – A coup plot by ex-government officials loyal to former Pres. Marcos and by a military faction loyal to Defense Minister Enrile, codenamed "God Save the Queen", is foiled by the government. After a failed coup attempt, Enrile is among the cabinet officials replaced by Pres. Aquino, Nov. 23.[2][3][9][13]
November 12–13 – Kilusang Mayo Uno leader Rolando Olalia and his driver, Leonor Alay-ay, are abducted by armed men in Pasig City, Nov. 12; are found dead in Antipolo, Rizal the following day. In connection with the murder, two soldiers are placed by the police under arrest as suspects, Dec. 1; a former AFP sergeant is arrested, Dec. 18.[2] Of the 13 Reform the Armed Forces Movement members charged with the murders, Eduardo Kapunan, Jr. would be acquitted in 2016; three of them would be convicted in 2021.[14]
November 27 – Government and rebel negotiators sign a 60-day ceasefire agreement, effective from Dec. 10, 1986 to Feb. 8, 1987.[2]
December
December 30 – AFP orders to arrest armed guerrillas entering populous areas.[2]
As per Act No. 2711 section 29,[16] issued on March 10, 1917, any legal holiday of fixed date falls on Sunday, the next succeeding day shall be observed as legal holiday. Sundays are also considered legal religious holidays. Bonifacio Day was added through Philippine Legislature Act No. 2946. It was signed by then-Governor General Francis Burton Harrison in 1921.[17] On October 28, 1931, the Act No. 3827 was approved declaring the last Sunday of August as National Heroes Day.[18] As per Republic Act No. 3022,[19] April 9 was proclaimed as Bataan Day. Independence Day was changed from July 4 (Philippine Republic Day) to June 12 (Philippine Independence Day) on August 4, 1964.[20]