However, the output of DOS command echo %date% looks not compatible between 2 Windows 2003 server: it's Thu 09/17/2009 on one box and 09/17/2009 Thu on another one.
Finally I figured out a CHCP command should be called to set the active code page number. It's usage is:
CHCP [nnn]Type CHCP without a parameter to display the active code page number.
nnn Specifies a code page number.
A test result is:
in code page 437, the output will be Thu 09/17/2009
in code page 936, the output will be 09/17/2009 Thu
So we know the trick now... :)