But the president left unclear what would happen after his term expires in May. He declined to clarify whether he would seek to remain in power until the election and whether he would seek reelection after seven years at the helm.
In accepting the date proposed by the independent election commission, Karzai appeared to resolve a dispute that has thrown Afghanistan's political transition into turmoil and raised doubts about the stability of this fragile, insurgent-plagued democracy.
But the president's confusing comments about whether he plans to continue leading the country until August and whether he intends to be a candidate left unresolved a second issue that could turn preparations for a smooth and orderly transfer of power into a political free-for-all.
"I accept the decision of the election commission," Karzai said at a news conference in his heavily guarded palace, reversing a decree he issued two weeks ago calling for elections to be held by April to comply with the constitution.
"If I continue in office, it should be legal," he said. "If it is not legal, my term ends and my work is over and I say goodbye to the people." When asked whether he would seek reelection, Karzai said he would do so "only if I can be a factor for stability and legitimacy, only if my candidacy makes people happy."
According to the constitution, elections must be held before the president's term expires, but there is wide agreement among Afghans and the country's international backers that the lack of security, funds and preparations make it impossible to hold credible polls until late summer or early fall.
Karzai's political opponents, who fear he will use his power in office to secure reelection, first complained that delaying the polls would give him an advantage. They have since accepted the postponement but say he should step down in May and establish a temporary form of rule until August.
"We think Karzai should end his term and be replaced by a neutral person. It's an opportunity to have more of a level playing field," said Anwar ul-Haq Ahady, a former central bank president who resigned to run for president. "It's great that he has accepted the commission's decision. It solves one crisis, but the second one is still looming. We need to be discussing who will replace him, not whether."