The Ukraine giant was forced to withdraw from the original bout last month after undergoing surgery to remove a kidney stone.
The Frenchman's camp have now confirmed the new date for the fight at the Esprit Arena, where Klitschko's WBA, WBO, IBO and IBF belts are on the line.
The rival management teams and promotors had agreed on a new date shortly after the initial bout was postponed.
But they were unable to announce the rearranged fight until it was given the approval of the IBF, who have finally ratified the contest.
Klitschko takes on the former world cruiserweight champion looking for his 50th knockout victory in his 60th professional bout.
Mormeck has fought only three times in the division since stepping up after losing his WBC and WBA cruiserweight titles to David Haye in 2007.