Those of you who have a biographical interest in Twain certainly know about
the massive two-volume publication _ Mark Twain Day By Day_ [Vol. I
(1835-1885), Vol. II (1886-1896)],  the fully annotated day-by-day
chronology of the life of Samuel L. Clemens.

What you may not know is that now all addenda/errata entries are posted
online, at:
http://marktwaindaybyday.webs.com

Holger