Precaution: Officials said the change was appropriate for 'any 82-year-old man'
Fears are growing for the health of the Pope after the Vatican announced that it would hold Christmas Eve Midnight Mass at 10pm this year.
Starting two hours earlier will allow 82-year-old Pope Benedict XVI 'time to rest' before his duties on Christmas Day, officials said.
It is the first time that the late night traditional Christmas Eve celebration has begun at any time other than midnight.
Vatican officials were quick to deny the Pope was in 'anything other than good health' but added: 'The change is just a precaution you would take for any 82-year-old man.
'He is very busy and the early start will mean an earlier finish.'
In the past Christmas Eve Midnight Mass has not ended until well after 2am and the Pope then has to be in St Peter's the following morning for the Christmas Day service and the noon Urbi et Orbi - 'to the city and to the world' - blessing.
Vatican commentators said that not even the late Pope John Paul II, who died in 2005, moved the midnight service, celebrating his last in 2004 at the traditional time.
It means that for the first time Christmas will be celebrated in Rome before Jerusalem.
The only service changed for Pope John Paul II was the Easter Vigil in the last years of his life but the Christmas service always remained at midnight.
Vatican expert Gian Guido Vecchi said: 'With the time difference it means it will be Christmas first in Rome and an hour later in Christ's birthplace of Bethlehem.'
Papal spokesman Father Federico Lombardi said: 'There is no cause for concern. The Pope is in good health. This was arranged a few months ago and relayed to broadcasters so they were aware for their planning.'
Earlier this year Pope Benedict fractured his wrist after slipping on a mat in his holiday home in the Italian Alps and fell over once before in the early 1990s but made a full recovery both times.
The Pope's hectic Christmas schedule begins tomorrow with the Festival of the Immaculate Conception and continues over the next few weeks leading up to Christmas, New Year and the Epiphany on January 6.
He also has trips planned next year to Malta, Cyprus, Portugal and the UK in autumn.
He has also planned visits across Italy, including Turin where he will open the year-long exhibition of the display of the Turin Shroud, said to have covered Christ at his burial.
On Friday he will also meet Irish bishops to discuss the abuse allegations that have rocked the Catholic Church in their country.
