I had to look up who the Culdees were. It appears that they were monastics without monastic vows — hermits who weren’t oath bound, but still lived in community for the sake of Christ. Oengus seems to have done what I’m doing — he composed a calendar of the saints and martyrs based on days, with a poem (I write sonnets, he wrote quatrains) for each day of a 365-day year. That opens the possibility of him having been a bard along the druidic model — a trained poet:
Oengus, composer of metrical days,
writer of verses in honor of saints:
by means of quatrains, you counted the ways
the people of God constrained their complaints
and lived in devotion to Christ the Lord.
We can imagine monks breaking their fast,
hearing your words read as they sat at board
and learning the saints’ deeds as each day passed.
Oengus help us to welcome each new dawn
with poetic kindness to those in need;
help us greet the saints with rhyme and song,
not just with word but also faithful deed.
for when Charity and Poetry meet,
our hearts become the Spirit’s mercy-seat.