St Patrick's Day moved to early date 

Confusion's expected to reign tomorrow as the Catholic Church marks St Patrick's Day three days early.

Catholic churches around the world are moving St Patrick's Day forward because the celebration falls during Holy Week this year - the most sombre week of the Church calendar.

St Patrick's Cathedral in Auckland is among the churches holding mass for the saint earlier than usual - it will be observed on Friday March 14 instead of the traditional March 17.

But the Bishop of Auckland - whose name and Cathedral are that of the saint - will be celebrating on both days.

Bishop Pat Dunn says he's aware a number of fans of St Patrick won't realise there's been a change, so he will be at the Cathedral on Monday as well.

He's confident he'll be able to blend both occasions.

The bishop says its not unusual to move major feasts if they clash.

It's the first time since 1940 that St Patrick's Day has fallen during Holy Week - and it will not happen again until 2160.

Celebrations and parades for the popular saint have also been moved in America, Australia, and Ireland - with the Pope's permission.