I actually did in a completely different way.
1. I created a post emaplte for the category I was working on.
2. I installed the plugin ‘Date Field’ http://matth.eu/wordpress-date-field-plugin. This enables a custom field to be created for your post with a date/time format.
3. Just before the loop I placed
query_posts($query_string. ‘&orderby=meta_value&meta_key=date_value&order=ASC’ );
Hope this helps someone.