On Sundays and other holy days of obligation, the faithful are to refrain from engaging in work or activities that hinder the worship owed to God.
In Australia, the Catholic faithful should observe as holy days of obligation:
- Christmas Day (December 25 – the Feast of the Nativity of Our Lord Jesus Christ)
- The Assumption (August 15 – the Feast of the Assumption of the Blessed Virgin Mary)
- All Sundays of the year
Early in the twentieth century Catholics used to observe 36 non-Sunday Holy Days, in addition to all Sundays of the year. This was reduced by a Motu Propio of Pope Pius X to the much lesser number of eight. These were:
- The Nativity of our Lord Jesus Christ
- The Epiphany
- The Ascension
- Holy Mary the Mother of God
- Her Immaculate Conception
- Her Assumption
- Saint Peter and Saint Paul the Apostles
- All Saints
In 1917, the Code of Canon Law raised this figure again, to a total number of 10 non-Sunday Holy Days (adding in the Feasts of the Body and Blood of Christ and Saint Joseph), however local Bishops were permitted the ability to alter the days in their dioceses.
Canon Law 1246 now provides that with the prior approval of the Apostolic See, the conference of bishops can suppress some of the holy days of obligation or transfer them to a Sunday.
In May 2001 the Australian Catholic Bishops Conference exercised this option and promulgated a decree announcing the only feast days to be observed as holy days of obligation are Christmas Day, the Feast of the Assumption and all Sundays of the year.
The decree was reviewed and confirmed by the Congregation for Divine Worship and Discipline of the Sacraments, and signed in January 2001 by its Prefect, Cardinal Jorge Medina Estevez.
The change became effective on 16 September, 2001 and remains in place.
Historically derived, holy days of obligation were special occasions on which Catholics, over the age of reason, were obliged to attend Mass. They were also encouraged to refrain from any work or involvement with commerce which would interfere with their participation in divine worship.
The number of holy days of obligation has changed greatly over time, cognisant of social change and the need for employment to support the family. For example in 1642, Pope Urban VIII greatly decreased the number to 36 from the much larger set which had been observed since the Middle Ages. Such a change enabled Catholics, many of whom were labourers in the fields, to more easily meet their obligations.