My understanding is that LC value should only be the standard date command with Latin characters.
First, is "date" the same as "/usr/bin/date"? Is there an alias for date? (if using csh).
% which date
% alias date
% date
% /usr/bin/date
If these check out, then is there a definition of LC_TIME in /usr/lib/locale/en_US.ISO8859-1? (this is the typical path).