The head of the Roman Catholic Archdiocese of New York attended services at Our Lady of Guadalupe Church of Monte Mario, which has led by Dolan since he was elevated to cardinal last year.

The Mass comes on the fourth Sunday of Lent, known as Laetare Sunday, or "Rejoice Sunday."

In an interview with Sirius XM, Dolan says there is much to celebrate.

"There is a spirit of joy. There's a spirit of joy among the College of Cardinals, because I think we have the seventh inning stretch today and we know the bottom of the ninth is in view. Because we're going to have the Mass of the Holy Spirit on Tuesday morning and we'll enter, officially, the conclave on Tuesday afternoon," Dolan said.

Final preparations for the conclave are underway in Vatican City.

A chimney installed at the Sistine Chapel will signal whether or not a new pope has been chosen.

White smoke means a pope has been elected and accepted his new position.

Black smoke indicates no candidate got the required two-thirds majority from the 115 voting cardinals.

They will hold a Mass Tuesday morning, then enter the Sistine chapel and hold their first round of anonymous balloting.

"The cardinals are completely free when they enter that chapel. That doesn't mean there isn't a human element involved in all this, because we are human beings on earth," said Vatican spokesman Thomas Rosica. "We're here in the flesh, walking on this ground, on this earth. Nevertheless, this is to be viewed as a deep, spiritual experience and not some sort of politician machination or political activity."

If no one is elected in the initial vote, cardinals will increase voting Wednesday, casting ballots twice in the morning and twice in the afternoon the rest of the week.

If no pope is elected by Friday, voting is suspended for Saturday, which would be a day of prayer.

Church officials hope to have a new leader in place before Holy Week, which starts on Palm Sunday, March 24.