I'm currently using the time of day plugin to modify the post times to a more human friendly format. However, users may have also noticed that the timestamps in the wp-admin interface are also modified. This is because, the plugin works via the filter hooks provided WP which processes output before displaying it to the user. The particular filter hook that I'm using (the_time) filters the output of the_time() functions.
Whilst this is used in most people's index.php file, it is also used in the wp-admin/edit.php file, and thus the dates here will also be filtered.
There is however a workaround: WP 1.5 provides another function get_the_time() which has two slightly different properties. Instead of displaying the time, this function now returns it. The second (and for us, the more crucial) property is that it isn't processed by the_time filter. Hence what we can do is to make the wp-admin/edit.php use this call instead and we'd have the best of both worlds.
In your wp-admin/edit.php, change the following line:
the_time('Y-m-d \<\b\r \/\> g:i:s a');
echo get_the_time('Y-m-d \<\b\r \/\> g:i:s a');
If you don't feel comfortable making the changes yourself and you're using WP 1.5, you can download my amended edit.php file. Rename your current wp-admin/edit.php to wp-admin/edit.php.old, upload this modified version and rename it as edit.php.