Future published / unpublished items are currently not kept in the queue, so the future publication won't take place.
In this fix is included in the solution.
To support delayed published times, use the 'time_execute' in the queue and check in the exporter if an document is published.
Also do the same for the 'Integrated\Bundle\SocialBundle\Connector\Twitter\Exporter'
Support publication start date and publication end date
Make sure the state is checked before executing the export. For the "add" state: when processing the queue the item can be unpublished, future published, past published or deleted. You have to check that again. For the "delete" state: when processing the queue the item can be published. So in both situations the state might be switched.
This should be taken care of in the file down beneath.