Under the Catholic Church's rules, the General Norms for the Liturgical Year and Calendar, the saint's feast day does not rank as high as the Monday before Easter and had to be moved (the last time Saint Patrick's Day had to be moved was in 1940 when it was changed to April 3 rd because it coincided with Palm Sunday, the first day of Holy Week).
In strict accordance with the rules, next year's St Patrick's Day should have been moved to the next available day in the Catholic Church's calendar, which is April 1st. But senior Irish clerics were anxious to keep the date as close as possible to the international civic celebrations, which are often planned many years in advance.
The group behind the St Patrick's Day celebrations in Dublin has announced that there would be no change to their plans for a parade on March 17.
Analysis: It is unclear, yet, if this will have an effect on the 2 principal regions where Saint Patrick's Day is an official public holiday (the Republic of Ireland, and Northern Ireland). Normally, as March 17 is a Monday, there would be no reason to move the public holiday, but we will continue to monitor further developments.