The Barddas of Iolo Morganwg, Vol. I., ed. by J. Williams Ab Ithel, [1862], at sacred-texts.com
It was in this way that they formerly computed time, and the divisions of day: they enumerated eight parts of the day, and three hours in each part, and reckoned thus, namely, the first hour, or the second, or the third hour of midnight, dawn, vapourlessness, &c., and so in respect of every one of the eight divisions.