According to a legal document signed by Benedict, cardinals will be allowed to move up the start date, if they arrive in Rome before the 15-day transition between pontificates.
On Monday, Britain's Catholic leader Cardinal Keith O'Brien said he wouldn't take part in the conclave to elect the next pope. His announcement to skip the conclave follows allegations printed in a British newspaper Sunday, accusing the cardinal of acting inappropriately with priests.
O'Brien also resigned as archbishop of St. Andrews and Edinburgh, though the Vatican insisted that Benedict accepted his resignation purely because he was nearing the retirement age of 75 - not because of the accusations.
But in a statement Monday, O'Brien said he didn't want to become the focus of media attention at such a delicate time for the church.
"Looking back over my years of ministry: For any good I have been able to do, I thank God. For any failures, I apologize to all whom I have offended," O'Brian said in his statement. "I do not wish media attention in Rome to be focused on me - but rather on Pope Benedict XVI and on his successor," O'Brien said. "However, I will pray with them and for them that, enlightened by the Holy Spirit, they will make the correct choice for the future good of the church."
His spokesman also said that he is contesting the allegations made by the British newspaper. No other details were released regarding the alleged inappropriate behavior.
It's the first time a cardinal has ever refused to participate in the conclave due to a personal scandal.
Los Angeles Cardinal Roger Mahony is currently facing backlash from grass-roots campaigns accusing Mahony of covering up for priests who raped and molested children. Mahony, however has defiantly said he would participate in the voting for the new pope.
The news regarding the Britain cardinal's resignation and the conclave changes come a day after a huge crowd of around 100,000 people stood in Saint Peters Square to receive a Sunday blessing from Pope Benedict XVI.
The papal apartment and the campaign to choose Benedict's successor will likely be sealed and underway by next week.
The Associated Press contributed to this report.