Dies natalis

Dies natalis is Latin for "birthday, anniversary" and may refer to:

• The birthday of an individual, or the anniversary of a founding event; see Glossary of ancient Roman religion#dies natalis
  • Dies Natalis Solis Invicti, the "birthday" of the Roman solar deity Sol Invictus on December 25
• the annual commemoration of a Christian martyr's death; see Calendar of saints
• Dies Natalis (cantata), a cantata by Gerald Finzi