There are three traditional feast days for honoring St. Dominic on the calendar of the order he founded: the translations of his relic (May 24th), the feast day proper (August August 8th in the revised calendar, formerly August 4th), and the miraculous appearance of a painting at the Convent of San Domenico in Soriano Calabria in 1530 (September 25, moved from September 15th).

Of these, May 24th, the Translation of St Dominic, is considered the most solemn of the solemnities. It marks the day when the bones of Dominic were moved to their new shrine in Bologna. They were said to bear a sweet scent that was still being reported 300 years later, and numerous miracles were attributed to them.

The following report comes Short Lives of the Dominican Saints (reparagraphed for ease of reading):

The body of the holy Patriarch, Saint Dominic, had  been laid to rest, according to his own desire, in the Church of Saint Nicholas at Bologna, beneath the feet of his Brethren, and, in spite of continual prodigies and Divine favours granted to the faithful who prayed  day and night at his tomb, his children allowed the  sacred deposit to remain under the plain flagstone originally laid over it and took no steps for obtaining his canonization. Lest they should be thought to be  seeking their own emolument under the appearance  of piety, the Friars even broke and threw away the votive offerings brought by the people, and would not permit any exterior marks of devotion to be exhibited.

It was necessity which at length compelled them to undertake the first translation of the sacred relics. The ever-increasing numbers of the Community obliged them to enlarge the Convent, and to pull down the old church and build a new and more spacious one. To do this the tomb of Saint Dominic would have to be disturbed. They accordingly applied for the requisite permission to Pope Gregory IX, who was no other than the Saint’s old friend, Cardinal Ugolino. He joyfully granted the petition, at the same time administering a sharp rebuke to the Friars May 25 for their long negligence.

The solemn translation accordingly took place on Whit-Tuesday, May 24, A.D. 1233, during the General Chapter, which was held that year at Bologna. The Pope wished to have attended in person, but, being prevented from doing so, he deputed the Archbishop of Ravenna to represent him, in company with a number of other distinguished prelates. Three hundred Friars Preachers from all countries assembled to assist at this function, not without a secret fear on the part of some as to the state in which the sacred remains might be found, as they had long been exposed to rain and heat, owing to the dilapidated condition of the church.

The opening of the tomb took place before daybreak, in the presence of Blessed
Jordan, then Master-General of the Order, and the Fathers of the Chapter, together with the Bishops, Prelates, and Magistrates who were to assist at the ceremony. All stood round in silence whilst the Procurator, Father Rodolph of Faenza, raised the stone.

Hardly had he begun to remove the earth and mortar that lay beneath than an extraordinary odour became perceptible, which increased in power and sweetness as they dug deeper, until at length, when the coffin appeared and was lifted out of the grave, the whole church was filled with the perfume as though from the burning of some rich and precious gums. The bystanders knelt on the pavement, shedding tears of emotion as the lid was raised, and the sacred remains, now reduced to bones, were exposed to their eyes.

It was the Master-General who raised the body of his beloved father and reverently laid it in a new coffin. The faithful were then admitted, and the Archbishop of Ravenna sang the Mass of the day, whilst the fragrance diffused from the open coffin flooded the whole of the sacred edifice.

Blessed Jordan in his circular letter to the Order thus describes the solemn function: “As the choir intoned the Introit, “Receive the joy of your glory, giving thanks to God, who has called you to the celestial kingdom,” the Brethren in their gladness of heart took the words as if spoken from heaven. The trumpets sounded, the people displayed a countless multitude of tapers; and, as the procession moved along, there everywhere resounded the words, “Blessed be Jesus Christ!”

He goes on to speak of the vast number of miraculous graces which were poured forth both before and after the ceremony. “Sight,” he says, “was granted to the blind, power of walking to the lame, soundness to the paralyzed, speech to the dumb. … I myself saw Nicholas, an Englishman, who had long been paralyzed, leaping at this solemnity.”

The coffin was then laid in the marble tomb prepared for it. But eight days later, to satisfy the devotion of some distinguished persons who had not been present on the previous occasion, the holy remains were again exposed to view. Then it was that Blessed Jordan, taking the sacred head between his hands, kissed it, whilst tears of tenderness flowed from his eyes; and, so holding it, he desired all the Fathers of the Chapter to approach and gaze at it for the last time. One by one they came and kissed the venerable relics.

All were conscious of the same extraordinary fragrance; it remained on the hands and clothes of those who touched or came near the body. Nor was this the case merely when the grave was first opened. The tomb remained unclosed for fifteen days, during which interval it was guarded by officers appointed by the city magistrates; and all this time the same exquisite odour was sensible to all who visited the spot; and Flaminius, who lived three hundred years later, thus writes (A.D. 1527): “This divine odour adheres to the relics even to the present day.”

A second translation of Saint Dominic’s relics took place in the year 1267, when the holy body was removed to a more richly ornamented tomb. This translation, like the first, was made at the time of the General Chapter ; and the head of the Saint, after being devoutly kissed by the Brethren and several Bishops who were present, was exposed to the veneration of the people from a lofty stage erected outside the Church of Saint Nicholas.

The tomb was again opened A.D. 1383, when a portion of the head was placed in a silver reliquary, in order the more easily to satisfy the devotion of the faithful. Finally, A.D. 1469, the remains of the Saint were deposited in the magnificently sculptured shrine in which they now rest, which is regarded as the masterpiece of Nicholas Pisano.

The other feast day also marks a miraculous event. On September 15th, 1530, three women appeared at the Convent of San Domenico in Soriano Calabria with a roll of canvas bearing a portrait of St. Dominic. In tradition, the three women are the Blessed mother, St. Catherine of Alexandria, and St. Mary Magdalene. Over the course of the next eight decades, more than sixteen hundred miracles were reported in association with the portrait, leading  Innocent XII to grant a feast (later suppressed) in commemoration.

Another miracle is attributed to Bl. Jane of Aza, the mother of St. Dominic. While her husband (Venerable Felix) was traveling, Jane gave away all the wine. Up his return, Felix heard of this, and so demanded wine for his guests and himself.

She quickly went to the cellar where the aforementioned wine was, and, kneeling, asked the Lord, saying: “Lord Jesus Christ, although I am unworthy to be heard on the basis of my merits, Yet hear me for the sake of your servant, my son, whom I have given over to your service.” For the mother knew the holiness of her son, and rising, fully confident, she went immediately to the jar and found it full of wine. Giving thanks to the Giver of all Graces, she had this wine served abundantly to her husband and others, and everyone was surprised!

Jane’s wine cellar is now a chapel at the convent founded in Caleruega, Spain on the site of Dominic’s family home.