It is officially called the Calendario Romano, or Roman Calendar. But on the streets of Rome, the annual line-up of strapping young men of the cloth is better known as the "hot priest calendar".
Tourists can often be seen expressing dismay as they stumble across the calendar adorning gift stands close to the Vatican, before snatching a peek, handing over €10 to the vendor and scurrying off.
But the Venice-based photographer behind the calendar, Piero Pazzi, insists the portraits are purely intended to promote the Eternal City and inform visitors about the Vatican.
They are all genuine priests, usually snapped in Rome during Holy Week, he tells The Local. He also travels to Seville to capture clergymen during the Spanish city's Holy Week procession.
“I meet most of them on the streets in Rome and ask to take their photos,” he says.
The priests do not supply their name but "most are happy to be photographed after I tell them the reason for the calendar," adds Pazzi, who launched the calendar in 2003.
"I do the same in Seville. Yes, the men are good-looking, but it is just a product, a way for people to be better informed about the Vatican.”
Indeed, the final few pages are dedicated to providing information about the centre of the Catholic Church, including its history of pontiffs, its museums and its chemist - “things that tourists in Rome, especially foreigners, do not have much knowledge about".
“For example, the chemist stocks mostly foreign medicines that you can’t find anywhere else in Italy. Not many people know about this. Anyone with a medical prescription can use it,” he says.
Pazzi adds that priests from all over the world are welcome to take part in the calendar, although they'll have to travel to Rome as most of the photographs are taken there.