[Evolution] evolution 'mail' won't display times correctly

[michael <cs networkingnewsletter org uk>]

I've had a look about but can't find a suitable solution so perhaps one
of you may be able to help.

When running evolution 2.10.3 under FC7 (2.6.22.4-65.fc7) I see that the
date for (eg) incoming messgaes is HH:MM AM/PM. How do I get this to be
in 24 hour format (instead of 01:01PM (is that how you would write it?!)
it says 13:01). 

I've tried variants of 
        LC_TIME=en_GB.UTF-8 /usr/bin/evolution
but with no joy.

Thanks, Michael