Why Is the Transfiguration of Jesus Celebrated on August 6?

"In 1456, Callixtus III extended the feast to the Universal Church in memory of the victory gained by Hunyady at Belgrade over the Turks, 6 August, 1456."

From Aleteia

By Philip Kosloski

While the transfiguration prepared the apostles for Good Friday, the feast was placed here for a number of reasons.

When the Gospels recall the event of Jesus' transfiguration, it is seen as a "precursor" to Jesus' suffering, death and resurrection.

Some scholars believe it took place during the Jewish Feast of Tabernacles, explaining why Peter was so eager to build a "tent" or "tabernacle" to house Jesus, Moses and Eljiah.

If this is true, then it would have been during September or October that the transfiguration occurred.

Preparation for Good Friday

Others believe the transfiguration took place closer to Good Friday, preparing his apostles for what would happen next.

St. Matthew and St. Luke place the transfiguration shortly before Jesus foretells his death and resurrection and the Roman Rite recalls the transfiguration at the beginning of Lent to emphasize this event as a preparation for Jesus' suffering and death.

However, historically this biblical event has been celebrated on August 6 for a number of reasons, as related by the Catholic Encyclopedia.

The Latin Church was slow in adopting this feast; it is not mentioned before 850 ... it was adopted in the liturgy about the tenth century in many dioceses, and was celebrated mostly on 6 August; in Gaul and England, 27 July; at Meissen, 17 March; at Halberstadt, 3 September, etc. In 1456 Callixtus III extended the feast to the Universal Church in memory of the victory gained by Hunyady at Belgrade over the Turks, 6 August, 1456. 

The Eastern Orthodox has celebrated the transfiguration similarly on August 6, adopting the earliest known date that it was included in the Church's calendar.

Symbolically, August 6 works well as it precedes the feast of the Exaltation of the Holy Cross on September 14 by 40 days.

As a result, it connects the transfiguration to the cross of Jesus Christ and helps us to see the glory in both. The transfiguration may not have historically occurred during August, but its feast makes spiritual sense in light of the other feasts that surround it on the liturgical calendar.