In the last national election, how many days did it take for the EMB to establish final results?

EU Election Observation Mission, Nigeria General Elections 2019, Second Preliminary Statement, 11 March 2019, accessed 21 April 2019

“On 27 February, INEC announced the official presidential results, with the incumbent, President Muhammadu Buhari from the All Progressives Congress (APC), winning with a sizeable margin of nearly four million votes.”