The Nuttall Encyclopedia
Astronomical tables drawn up at Toledo by order of Alfonso X. in 1252 to correct the anomalies in the Ptolemaic tables; they divided the year into 365 days, 5 hours, 49 minutes, 16 seconds.
Wood, James, ed. Entry for 'Alfonsine Tables'. The Nuttall Encyclopedia. https://www.studylight.org/encyclopedias/eng/nut/a/alfonsine-tables.html. Frederick Warne & Co Ltd. London. 1900.