Presidential elections to find a successor to Lech Kaczynski, who was killed in a plane crash, will be held in Poland on 20 June.
The poll date was set by acting President Bronislaw Komorowski, his spokesman said.
The BBC reports Mr Komorowski and the late president's twin brother, Jaroslaw, are expected to be the main candidates.
If no candidate gets at least 50% of the vote in the first round, a run-off will be held on 4 July.
Lech Kaczynski and 95 other senior Polish officials died on 10 April when their plane crashed in western Russia en route to a memorial for about 22,000 Poles massacred by Stalin's secret police at Katyn in World War II.
Investigators believe pilot error caused the plane to hit treetops in heavy fog in the Smolensk region.
On Sunday, Mr Kaczynski and his wife Maria were buried in a crypt in the Wawel Cathedral in Krakow after a state funeral.