Some don’t know, and understandably so, that the Church recognizes many great figures of the Old Testament as saints, and she gives them feast days. They may not appear on the general calendar for liturgical observation, but they are listed in the Roman Martyrology.
As the first part of Advent closes and we move into the heavier Advent days of final preparation we have three ancient Prophets. On 16 Dec St. Haggai. On 18 Dec. St. Malachi.
Today, however, we have St. Daniel. And along with Daniel Sts. Ananias, Azarias, and Misael, the three boys in the fiery furnace. I think some sources placed them on 16 December.
Here is a shot of my Roman Curia wall calendar.