@FoolforBooks: A difference of an hour doesn't matter, but if the Kindle clock has reset to 1970 after a crash, that's a problem. For Recently Read, I use the 'last modified' timestamp on the .mbp file to learn when the book was last accessed. The code is looking for the last 30 days of books read. So the one-hour difference doesn't matter.
It is in fact possible to change the Kindle clock with a hack.
This thread explains how to do it.
Thanks for the followup.
G