6 December Saint Nicholas Day, also called the Feast of Saint Nicholas, is observed on 5 December or on 6 December in Western Christian countries, and on 19 December in Eastern Christian countries using the old church Calendar.

PERSONENT HODIE

Saint Nicholas Day from Wikipedia   https://en.wikipedia.org/wiki/Saint_Nicholas_Day
Personent hodie from Wikipedia  https://en.wikipedia.org/wiki/Personent_hodie
Personent hodie from Classic fm    https://www.classicfm.com/discover-music/occasions/christmas/first-santa-song/
Intonent hodie voces ecclesiae- Anonymous 4 https://www.youtube.com/watch?v=bJSUDI0f880