FYI this comment is not going to prevent a merge.

What about pushing the knowledge of delete all the way into the `JobStoreService` rather than just providing it with a list? So rather than asking it for a list to delete you tell it to delete whatever based on the number of days to keep items prior to a given date?

e.g.

```
jobStoreService.delete(grailsApplication.config.job.cleanup.daysToKeep, DateTime.now())
```

```
class JobStoreService {
    def delete(daysToKeep, priorTo) {
        // List and delete in here
    }
}
```