Zimbabwe's Constitutional Court will hear the opposition's legal challenge to the election of President Emmerson Mnangagwa on August 22, the ruling party said on Thursday.
The main opposition Movement for Democratic Change (MDC) is suing the ZANU-PF party and election commission over alleged fraud in the July 30 vote.
The ballot was Zimbabwe's first poll since the resignation of long-time ruler Robert Mugabe.
"The matter is going to be heard on Wednesday," Paul Mangwana, a member of ZANU-PF's legal team, told AFP.
"It should take a day -- two days at the most."
MDC spokesman Nkululeko Sibanda confirmed the hearing was set for Wednesday after the court held a case management hearing.
Mnangagwa, who succeeded Mugabe, narrowly won the presidential race with 50.8 percent of the vote -- just enough to avoid a run-off against the MDC's Nelson Chamisa, who scored 44.3 percent.
His inauguration, which had been planned for Sunday, was postponed pending the court's ruling.
Mnangagwa had vowed the elections would be free, fair, and turn the page on Mugabe's often repressive 37-year rule.
But the southern African nation was thrown into turmoil when the army opened fire on activists protesting alleged fraud, killing six.
The bloodshed was followed by a crackdown on the opposition.
Analysts say that MDC's legal challenge has little chance of success given the courts' historic leaning towards ZANU-PF, which has ruled since independence from British colonial rule in 1980.
Judges have 14 days from August 10 to rule on the case. Their options are to confirm the results; declare another candidate to be the winner; or invalidate the results.
In the latter case, elections would be held within 60 days and if no candidate is found to have won by a simple majority, a run-off could be ordered.