We are using the extra field to display dates in the future vice the posting
date. This way the News module can display news or future events.

It works very well except for an undefined variable error generated by the
summary template on line 72.  This occurs for all posts where the extra field is
empty i.e. the display date is the post date.

It appears that the summary template does not test each post for an extra value,
or that a null value is not generated for empty extra fields.

We can work around the error by simply entering a date in the extra field for
every event, so just raising it in case the module gets re-worked in the future.