There is a fascinating new book out: Caesar's Calendar: Ancient Time and the Beginnings of History (Sather Classical Lectures) by Denis Feeney (University of California Press 2007, 386 pages, list price $29.95).
I haven't had the chance yet to read much of it, although what I have read I do like. The book has just received a very favorable review at Bryn Mawr Classical Review which I'd like to share:
Bryn Mawr Classical Review 2007.09.17
The reviewer, Christopher Smith, University of St Andrews, calls it “a tremendously important as well as a terrifically well-written book.”