Create a date hyperdb property on issue.
Set a timezone for the 
user (I use -5).

When in edit mode on an issue, enter a 
date.

It is interpreted with respect to the local 
timezone
which is correct, but it is not displayed with the 
timezone correction in the edit box. I.E. If I type in 2003-02-28,
I 
get 2003-02-27.19:00:00 with the user's timezone set
to -5. I 
use:

       <td tal:content="structure 
python:context.duedate.field(size=20)">
       duedate</td> 


to display the edit box. It should be displayed as:
2003-
02-28.00:00:00.

Maybe 
a:

python:context.duedate.field(size=20, 
tzcorrect=1)

like function is needed.