Remember, you can check the full document Paschale Solemnitatis on this site, among many on the internet.
Today we take a brief look at the Chrism Mass. Sometimes this is celebrated prior to Passion Sunday, sometimes during Holy Week. Not often on Holy Thursday itself, but there are exceptions to that.
A note for clergy of the diocese:
35. The Chrism Mass, which the bishop concelebrates with his presbyterium, and at which the Holy Chrism is consecrated and the oils blessed, manifests the communion of the priests with their bishop in the same priesthood and ministry of Christ. (Presbyterorum Ordinis. 7) To this Mass, the priests who concelebrate with the bishop should come from different parts of the diocese, thus showing in the consecration of the Chrism to be his witnesses and cooperators, just as in their daily ministry they are his helpers and counsellors.
… and for the laity:
The faithful are also to be encouraged to participate in this Mass, and to receive the Sacrament of the Eucharist.
Traditionally the Chrism Mass is celebrated on the Thursday of Holy Week. If, however, it should prove to be difficult for the clergy and people to gather with the bishop, this rite can be transferred to another day, but one always close to Easter. (Ceremonial of Bishops, 275) The Chrism and the Oil of Catechumens is to be used in the celebration of the sacraments of initiation on Easter night.
There are challenges all over for this Mass. In my parish, there was no Mass on Tuesday of Holy Week because all the clergy had left for the cathedral. But a Mass during the day makes it difficult for working men and women to attend. An evening Mass, in turn, means late night travel for anyone coming from a distance.
A bishop or diocese is not permitted more than one celebration:
36. There should be only one celebration of the Chrism Mass given its significance in the life of the diocese, and it should take place in the cathedral or, for pastoral reasons, in another church (Cf. Ceremonial of Bishops, 270) which has a special significance.
This piece is a significant connection for people and their bishop:
The Holy Oils can be brought to the individual parishes before the celebration of the evening Mass of the Lord’s Supper, or at some other suitable time. This can be a means of catechizing the faithful about the use and effects of the Holy Oils and Chrism in Christian life.
I’d say catechesis is largely complete on which oils are used for which sacrament. Although I did know a priest who insisted on using chrism for the pre-baptismal anointing. That was strange.
The presentation of oils provided by the USCCB gives a basic explanation of the oils in context of a procession. I’ve found this ritual works well.
Catholic Sensibility 
The advantage of sticking to the morning of Holy Thursday is that no *other* Masses, including ritual Masses (like funeral Masses) are celebrated that morning.
Way back, before Trent, used to be three Masses on Holy Thursday, the lost one being for the reconciliation of penitents. Interestingly, that one appears to have been considerably older in the Roman rite than the Mass of the Lord’s Supper, which didn’t make an appearance until the 7th century.
Liam,
Is there any book or resources that you use to come up with these little interesting factoids?
Not one particular one, no. There’s so much I run across over the decades in my studies and ongiong reading.
(If, however, you want scholarly citations, then that’s for a different medium than casual comboxing.)