Excerpti: The Homily, Part II: When should there be a homily?

This is the second post in the Excerpti (extracts) series on the homily. This is Part II: When should there be a homily?

Summary
Apart from Canon Law, the main sources here are Sacramentum Concilium and Inter oecumenici.

• A homily is to be given on every Sunday and every holyday of obligation, and only a grave reason can justify its omission. This includes masses with children where they have their own Liturgy of the Word. (Cf. CIC, can. 528 §1, 767 §2; CCEO, can. 614 §2; Directorium de missis cum pueris, n. 17)
• A homily is strongly recommended during the week, especially during Advent and Lent, on a feast day or occasion of grief, and whenever there are a sufficient number of people present. (Cf. CIC, can. 767 §3)
• Every celebration of marriage must include a homily, even if the marriage is celebrated outside of Mass. (Cf. Inter Oecumenici, nn. 70, 74/a)
• Celebrations of baptism, penance, and funerals are fitting occasions for a homily as well. (Cf. Catechesi Tradendae, n. 48)
  

Western Canon Law
"The parish priest ... is therefore to see to it that the lay members of Christ's faithful are instructed in the truths of faith, especially by means of the homily on Sundays and holydays of obligation and by catechetical formation." (CIC, can. 528 §1)

"At all Masses on Sundays and holydays of obligation, celebrated with a congregation, there is to be a homily and, except for a grave reason, this may not be omitted." (CIC, can. 767 §2)

"It is strongly recommended that, if a sufficient number of people are present, there be a homily at weekday Masses also, especially during Advent and Lent, or on a feast day or an occasion of grief." (CIC, can. 767 §3)

Eastern Canon Law
"The homily ... is strongly recommended as part of the liturgy itself." (CCEO, can. 614 §1)

"Parish priests and rectors of churches have the obligation to take care that a homily is given at least during the Divine Liturgy on Sundays and feast days and that it is only omitted for a grave reason." (CCEO, can. 614 §2)

Other Documents
"[T]he holy Synod charges pastors, and all who have the cure of souls, that they frequently, during the celebration of mass, expound either by themselves, or others, some portion of those things which are read at mass, and that, amongst the rest, they explain some mystery of this most holy sacrifice, especially on the Lord's days and festivals." (Council of Trent, 1562 - Session XXII, Chapter VIII)

"Let priests therefore ... assiduously" -- that is, unceasingly -- "distribute the heavenly treasures of the divine word by sermons, homilies and exhortations[.]" (Pope Pius XII, 1943 - Divino Afflante Spiritu, n. 50)

"[T]he homily, therefore, is to be highly esteemed as part of the liturgy itself; in fact, at those Masses which are celebrated with the assistance of the people on Sundays and feasts of obligation, it should not be omitted except for a serious reason." (Second Vatican Council, 1963 - Sacrosanctum Concilium, n. 52)

"There shall be a homily on Sundays and holydays of obligation at all Masses celebrated with a congregation, including conventual, sung, or pontifical Masses. On days other than Sundays and holydays a homily is recommended, especially on some of the weekdays of Advent and Lent or on other occasions when the faithful come to church in large numbers." (Sacred Congregation of Rites, 1964 - Inter Oecumenici, n. 53)

"Unless there is some good, excusing reason, marriage shall be celebrated within Mass, after the gospel and homily. The homily is never to be omitted." (Sacred Congregation of Rites, 1964 - Inter Oecumenici, n. 70)

Regarding the celebration of marriage outside of Mass: "After the reading of the epistle and gospel from the Missa pro sponsis, there shall be a sermon or homily based on the sacred text. {Cf. Sacrosanctum Concilium, n. 52}" (Sacred Congregation of Rites, 1964 - Inter Oecumenici, n. 74/a)

"[P]riests are to give a homily whenever it is prescribed or seems advisable[.]" (Sacred Congregation of Rites, 1967 - Eucharisticum Mysterium, n. 20)

"On the Saturday evening, the Mass is to be celebrated as assigned in the calendar for Sunday and the homily ... [is] not to be omitted. (Sacred Congregation of Rites, 1967 - Eucharisticum Mysterium, n. 28)

"Sometimes ... it will be appropriate to celebrate the liturgy of the word, including a homily, with the children in a separate, but not too distant, room." (Sacred Congregation for Divine Worship, 1973 - Directorium de missis cum pueris, n. 17)

"The homily explaining the word of God should be given great prominence in all Masses with children." (Sacred Congregation for Divine Worship, 1973 - Directorium de missis cum pueris, n. 48)

"The homily should have its place not only in every Sunday and feast-day Eucharist, but also in the celebration of baptisms, penitential liturgies, marriages and funerals. This is one of the benefits of the liturgical renewal." (Pope John Paul II, 1979 - Catechesi Tradendae, n. 48)

Hear that? Homilies on a regular basis and even more frequently than that are "one of the benefits of the liturgical renewal". So don't skip the homily!

"There is to be a homily on Sundays and holy days of obligation at all Masses that are celebrated with the participation of a congregation; it may not be omitted without a serious reason. It is recommended on other days, especially on the weekdays of Advent, Lent, and the Easter Season, as well as on other festive days and occasions when the people come to church in greater numbers. {Cf. Inter Oecumenici, no. 53}" (GIRM, n. 66)