However, after the primaries, campaigns only start formally on November 18, INEC said.
Parties are expected to collect forms for all the elections at the INEC headquarters between August 17 and 24.
The chairman said that the last date for submission of nomination forms by political parties has also been scheduled for December 3 for president and NASS elections, and state elections December 17. The elections into Abuja Area Councils also hold on March 2.
Presidential and national assembly elections will hold on February 16th, 2019, while the governorship, state assembly and area council elections in the federal capital territory will take place on March 2, 2019.
The presidential and National Assembly elections will hold on same day on February 16, 2019, INEC said while briefing journalists on Tuesday.
Campaigns for the governorship and state assemblies are scheduled to commence on December the 1, 2018.
The commission is faced with two conflicting court judgement on the Anambra seat that has been vacant since the Court of Appeal sacked Uche Ekwuenife of the Peoples Democratic Party, PDP, in December 2015.
He added that the commission needed the support and cooperation of all stakeholders to succeed, saying the commission expects full adherence to the provisions of the Constitution and the Electoral Act which formed basis of the timetable.
"Today is exactly 402 days to the opening of polling units nationwide at 8 a.m on Saturday Feb. 16, 2019".
The INEC boss urged all the political parties and all and sundry "to eschew bitterness and conduct their activities with decorum".
When asked how much the election would cost, he said, "This is being finalised and we will conclude when we meet on Thursday and thereafter, we can say how much the election will cost and we will finalise on the election budget and this will be known (to the public)".
In the said letter obtained by our correspondent, the senior lawyers warned the Commission of the legal consequences of proceeding with the rerun election in the face of a subsisting consent judgment of a Federal High Court in Abuja which declared Dr. Obiora Okonkwo as victor of the seat is set aside.
He also disclosed that over 100 political associations had applied to INEC to be registered as political parties.