A conclave to elect the next pope will start on May 7, the Vatican said on Monday. Scores of cardinals gathered to decide when cardinal-electors will meet in the Sistine Chapel to vote for a successor to Pope Francis, who died last week at 88.

Only cardinals under the age of 80 are eligible to vote in the secret ballot. Out of the 252 current cardinals, most appointed by Francis, over 130 can vote. A two-thirds majority is needed to elect a new pope, and cardinals are not allowed to leave the conclave until a successor is named, except in rare cases.

Generally, the conclave must begin 15 to 20 days after the pope’s death. In the last conclave, Francis was elected in two days.