[exim] Date: header in non-english format

Hi!

I'm receiving bounce messages from my Exim server with Date: header in
spanish language, something like this:

Date: jue, 23 ago 2007 14:35:06 +0200

Only bounce messages have Date header: in spanish. All another cases have
Date: header in english.

Server's locales are this:
LANG=es_ES@euro
LANGUAGE=es_ES:es:en_GB:en
LC_CTYPE="es_ES@euro"
LC_NUMERIC="es_ES@euro"
LC_TIME="es_ES@euro"
LC_COLLATE="es_ES@euro"
LC_MONETARY="es_ES@euro"
LC_MESSAGES="es_ES@euro"
LC_PAPER="es_ES@euro"
LC_NAME="es_ES@euro"
LC_ADDRESS="es_ES@euro"
LC_TELEPHONE="es_ES@euro"
LC_MEASUREMENT="es_ES@euro"
LC_IDENTIFICATION="es_ES@euro"
LC_ALL=

But I have other servers with the same locales and they have not the same
problem with Date: header.

How can I change Date: header format or language?

Thanks!