There has been some confusion as to the scheme of the balloting when the conclave is prolonged. Universi Dominici gregis 74 specifies that "in the event that the Cardinal electors find it difficult to agree on the person to be elected, after balloting has been carreid out for three days in the form described above without result, voting is to be suspended for a maximum of one day in order to allow a pause for prayer…"
When Fr. Federico Lombardi clarified that this day of reflection (if no pope has been elected) would be carried out on Saturday, many people were surprised. The "three days" of balloting do not include Tuesday, the first day of the conclave, even though there is one ballot on that day. This has always been clarified in the handbook Sede Apostolica Vacante, published by the Office for the Liturgical Celebrations of the Supreme Pontiff (2005). Since not many people have access to this Italian book, I'll reproduce the scheme of the balloting:
|1 (Tuesday, March 12)||Mass for the election of the Pope||1st scrutiny|
|2 (Wednesday, March 13)||2nd, 3rd scrutinies||4th, 5th scrutinies|
|3 (Thursday, March 14)||6th, 7th scrutinies||8th, 9th scrutinies|
|4 (Friday, March 15)||10th, 11th scrutinies||12th, 13th scrutinies|
|5 (Saturday, March 16)||A day of prayer, informal discussion among the voters, and a brief spiritual exhortation given by the senior Cardinal-Deacon (Cardinal Jean-Louis Tauran)|
|6 (Sunday, March 17)||14th, 15th scrutinies||16th, 17th scrutinies|
|7 (Monday, March 18)||18th, 19th scrutinies||20th scrutiny|
|8 (Tuesday, March 19)||A day of prayer, informal discussion among the voters, and a brief spiritual exhortation given by the senior Cardinal-Priest (Cardinal Godfried Danneels)|
|9 (Wednesday, March 20)||21st, 22nd scrutinies||23rd, 24th scrutinies|
|10 (Thursday, March 21)||25th, 26th scrutinies||27th scrutiny|
|11 (Friday, March 22)||A day of prayer, informal discussion among the voters, and a brief spiritual exhortation given by the senior Cardinal-Bishop (Cardinal Giovanni Battista Re)|
|12 (Saturday, March 23)||28th, 29th scrutinies||30th, 31st scrutinies|
|13 (Sunday, March 24)||32nd, 33rd scrutinies||34th scrutiny|
From the new motu proprio Normas nonnullas, if the 34 votes do not result in an election, one day shall be dedicated to prayer, reflection and dialogue. In the next balloting only the two names which received the greatest number of votes in the previous scrutiny will be voted upon, and the two cannot vote. This takes place until the two-thirds majority is reached.
What happens if this still results in a stalemate? Canon lawyers suggest that the cardinals can decide to throw away these two names, and have another open balloting again, and later again resort to restriction to two names if necessary.
From recent history, conclaves have been relatively short. Since 1846, the conclaves have never lasted longer than 5 days. I expect this time the new Supreme Pontiff will be elected in 5 votes.