VATICAN CITY — It is possible the world's cardinals will not begin meeting at the Vatican until March 4, and they cannot set a start date for the conclave until they have met, the Vatican spokesman said.The conclave ballot reads on top “Eligo in Summum Pontificem” (“I elect as Supreme Pontiff”). This unused ballot is from a collection of documents retained by U.S. Cardinal William H. Keeler from the 2005 conclave.  (CNS photo/Nancy Phelan Wiechec)

Jesuit Fr. Federico Lombardi, Vatican spokesman, said Cardinal Angelo Sodano, dean of the College of Cardinals, will send out letters March 1 – a Friday – formally informing the world's cardinals that the papacy is vacant and calling them to meet at the Vatican.

"It is likely they will not meet Saturday or Sunday," he said, so the meetings are unlikely to begin before Monday, March 4. As of Feb. 26, he said, it was impossible to say how long the cardinals would want to meet before they feel ready to announce a date for the conclave to begin.

The formal convocation, he said, will be sent by email or fax for immediacy, but hard copies will be mailed to the cardinals' permanent residences so they'll have a copy for their archives.

In addition, he said, while many cardinals were arriving in Rome before the papacy ended Feb. 28, "the cardinals will not live at the Domus Sanctae Marthae," the Vatican guesthouse used during the conclave – "until almost the eve of the conclave."

The rooms must be cleaned, the televisions and telephones disconnected and the place swept for listening devices, Fr. Lombardi said. "It's completely normal."

Another reason why they don't move in right away, he said, is because the rooms – either simple singles or suites – are distributed by lot once the majority of the cardinals are present.