Feast of St Thomas, Apostle of Christ, Christmas Novena to the Christ Child, Day Six, Notre-Dame de Saint-Acheul / Our Lady of Saint Acheul, Amiens, France, (4th Century) and Memorials of the Saints – 21 December

Feast of St Thomas, Apostle of Christ
His Feast was moved to 3 July in 1969
https://anastpaul.com/2018/07/03/saint-of-the-day-feast-of-st-thomas-apostle-of-christ/
AND:
https://anastpaul.com/2019/07/03/feast-of-st-thomas-apostle-of-christ-martyr-3-july/
AND:
https://anastpaul.com/2017/07/03/saint-of-the-day-3-july-st-thomas-the-apostle-of-christ/

Christmas Novena to the Christ Child, Day Six:
https://anastpaul.com/2018/12/21/christmas-novena-to-the-christ-child-day-six-21-december-2/

Notre-Dame de Saint-Acheul / Our Lady of Saint Acheul, Amiens, France, founded by Saint Firmin, Bishop (4th Century) – 21 December:

The Church containing the Shrine of Our Lady of Acheul, was located near Amiens. In fact, Saint Acheul was once considered the Mother-Church of the Cathedral of Amiens and was sometimes called the “Old Cathedral of Amiens,” although this is no longer the case, as there is now a larger Cathedral Church in Amiens.
The Church stands on the very place where once a Roman temple stood, and tradition tells that Saint Firminus (Died 303) was the Apostle of Amiens, arriving there before the close of the third century after Christ. It is said that by the eloquence of his preaching and the number of his miracles, Saint Firminus (or Saint Firmin) converted many idolaters to the True Faith and Baptised three thousand men in forty days.
The early Church, built around the year 300, contained the remains of the Martyred Saint. This Church was devastated repeatedly by the invasions of the Normans, and was finally totally destroyed in 1218. The relics of Saint Firmin were transferred to the Cathedral of Amiens during the Middle Ages.
The Shrine of the Virgin of Saint Acheul, is noteworthy for a singular miracle – an apparition which occurred during the Holy Sacrifice of the Mass. The celebrant, after the Consecration, saw a hand appear from within a luminous cloud and the hand of Christ took the Sacred Host and dropped it into the Chalice. Some of the faithful present likewise witnessed the same thing – a certain skeptic was brought to his knees in humble acceptance of the fact, that the Holy Sacrifice is truly the same as that of Calvary. The armorial bearings of the Abbey of Saint-Acheul, displays a hand in remembrance of this miracle.

The present Cathedral of Saint Acheul was not finished until the fifteenth century. After the erection of the new Cathedral at Amiens, Saint Acheul was known as the Church of Our Lady of Acheul. Miracles took place frequently and pilgrimages continued.
The Church of Saint Acheul was destroyed by a natural phenomenon, probably a strong storm, in about the year 1751. It was rebuilt and completed in 1760. A few short years later, during the Terror of the French Revolution, the Church was used as a stable.
Today, the Church is protected as an historical monument, the decree given in 1969. The Abbey buildings are now occupied by a private party but the Church is used as a Parish Church.

St Peter Canisius SJ (1521-1397) Doctor of the Church (Optional Memorial)
His Feast day is 27 April (General Roman Calendar, 1926–1969.
Biography:
https://anastpaul.wordpress.com/2017/12/21/saint-of-the-day-21-december-st-peter-canisius-s-j-1521-1397-doctor-of-the-church/
AND Pope Benedict’s Catechesis on St Peter Canisius:
https://anastpaul.com/2018/12/21/saint-of-the-day-21-december-st-peter-canisius-s-j-1521-1397-the-second-apostle-of-germany-doctor-of-the-church/

Bl Adrian of Dalmatia

St Anastasius II of Antioch (Died 609) Bishop and Martyr, Confessor, Defender of the Faith.
https://anastpaul.com/2020/12/21/saint-of-the-day-21-december-saint-anastasius-ii-of-antioch/

St Anrê Tran An Dung
St Baudacarius of Bobbio
St Beornwald of Bampton
Bl Bezela of Göda
Blessed Daniel of the Annunciation OdeM Mercedarian Friar (13th Century?)
St Dioscorus

Blessed Dominic Spadafora OP (1450-1521) Dominican Priest, renowned Preacher and Evangelist. His body is incorrupt.
Biography:
https://anastpaul.com/2019/12/21/saint-of-the-day-21-december-blessed-dominic-spadafora-op-1450-1521/

St Festus of Tuscany
St Glycerius of Nicomedia
St James of Valencia
St John of Tuscany
St John Vincent
St Micah the Prophet
St Phêrô Truong Van Thi
St Severin of Trèves (Died c 300) Bishop, Confessor
Bl Sibrand of Marigård
St Themistocles of Lycia