Q:

use find command to display file last modified at a particular time

I'v been googling and reading the man page but I do not see the ability for find to display a file modified at a particular time. 
so I have a time stamp like "2012-09-16 08:10:01 PM".   I want to look through a directory and find a file modified at that time.   
I was hopeing find can do this. 

A:

find <DIR> -newermt '<DATE1>' \!  -newermt '<DATE2>'
for more details you can read the man page for find, search in it for newerXY option
.... !  means not. 
So the above command is interpreted as: find files in <DIR> that are newer than <DATE1> and not newer than <DATE2>. 
Also note that some older versions of find do not have -newerXY.  In that case you have to create two files with touch (touch allows you to specify a date) and use find <DIR> -newer <your ref file > \!  -newer <your ref file 2>

