In Western Christianity, The Feast of Saint Luke the Evangelist, who was a Greek physician who lived in Antioch, honors him as one of the Four Evangelists (the four traditionally ascribed authors of the canonical Gospels) and as the author of the Gospel of Luke and the Acts of the Apostles, which together account for over a quarter of the text of the New Testament.
This day is traditionally observed as a Feast, which includes reciting the Gloria.
Here are some ways you can observe this day according to Western Christian tradition: