The Chrism Mass is the annual event where the Bishop blesses the three Holy Oils used in the administration of blessings and sacraments throughout the year.
Traditionally, the Chrism Mass takes place on Holy Thursday morning, but in dioceses which cover a relatively large territory such as ours, it is often held at another time near Holy Week.
The traditional day is chosen because it is the day of the Institution of the Eucharist, and so in a special way at the Chrism Mass we also remember the institution of the priesthood. As the priests of the diocese gather with their bishop for the Mass, they also renew the promises they made on the day of their ordination.