A.D. 2100 December 19–25
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday, December 19
- The Fourth Sunday in Advent
- O Clavis David
Monday, December 20
- The Fourth Monday of Advent
- Eve of Saint Thomas
- O Oriens
Tuesday, December 21
- Saint Thomas, Apostle and Martyr
- The Fourth Tuesday of Advent
- O Rex Gentium
Wednesday, December 22
- The Fourth Wednesday of Advent
- O Emmanuel
Thursday, December 23
- The Fourth Thursday of Advent
- O Virgo Virginum
Friday, December 24
- The Fourth Friday of Advent
- Christmas Eve
Saturday, December 25
- The Nativity of our Lord (Christmas Day)