To fix the event duration showing as 0 hours for a 30-minute event, follow these steps:

1. Navigate to the event page on Decile Hub.
2. Click on "Event Details" or the equivalent section where you can edit the event information.
3. Look for the duration field and ensure it is set correctly to 30 minutes.
4. Save the changes.

If the issue persists, contact Decile Hub support for further assistance.