Hello everyone!
Sasami-chan wrote:
> The two characters on the lower half are used to
> denote the date and the hour on which 
> Kenshin-dono was born. In this case, "yi wei" 
> indicates that he was born on a "yi" day, and in
> between 13:00 ~ 15:00. Specifically, "yi" is
> the ten Heavenly Stem and "wei" is the eighth 
> of the twelve Earthly Branches. (Did Kenshin-
> dono told you his birthday? ^_-)
Again, Sasami-chan made a mistake. *^^* Better 
step in and pull the buzzard out of the sky 
before somebody else does. ^_-

"Yi wei" points to a specific day.

You can find more information on the
Heavenly Stem and Earthly Branch here:
http://www.chineseastrologyonline.com/StemBranch.htm
There is a pretty cool Chinese Fortune-Telling Calendar 
system there, I recommend everyone to give it a try.

Have fun! ^_^

CheerS!
Sasami-chan