The Barddas of Iolo Morganwg, Vol. I., ed. by J. Williams Ab Ithel, , at sacred-texts.com
Twenty-nine years of the sun are thirty years of the moon.
The days of the lunar year are 354.
The days of the solar year are 366.
The days of the year of memorial and computation, 365. Others say, 364.
It is called memorial and computation, information and computation, since the Cymry have come into the Isle of Britain.