Montmouthshire Day takes place each year on 25 September, the feast of Saint Cadoc or Cadog (born c. 497).
Cadoc was the founder of the monastery of Llancarfan, and a pioneer of Celtic Christianity in Wales.
Caernarfonshire Day takes place annually on 28 November.
It commemorates the death of Prince Owain Gwynedd, King of Gwynedd (1137–70).