Best Practices

Hello, I'm in the process of building a site that sells tickets to events using ubercart. I'd like to be able to have a rule that automatically unpublishes the event node when the event date passes.

For the most part, I've been able to do this but there's still a question in my mind as to whether or not I've done it the best way. Here's a quick synopsis of what I did:

1. Created an "event" content type (actually an ubercart product class).
2. Added a date field to the "event" content type (field_dates).
3. Created a rule that is run on cron.
4. I did not include any conditions.
5. For the rule's action, I wrote a snipped of PHP code that queries the node table or the published nodes of the "event" type that have a field_dates value in the past and unpublished any that it found.

Is this the best way of accomplishing this using the Rules module?

I've attached an export of the rule in case anyone is interested.

Thanks,
-mike