Reckoning of Years
The Reckoning of Years was a book written by Merry Brandybuck sometime after the War of the Ring. It this work Merry discussed the relation of the calendars of the Shire and Bree to those of Rivendell, Gondor, and Rohan. This book was one of the important tomes kept in the library of Bucklebury. Some of the information contained in this work was probably translated and used by J.R.R. Tolkien when he wrote "Appendix D" of The Lord of the Rings.