Setting to publish a change at a specific time

It would be great if you had the option for a new version of a workflow to be published at a specific time (as well as the current immediate option). This would assist with rolling out changes to a widely used form where it is communicated that the change will occur at a specific time.
This could work by providing the option on the publish screen of 'Do you want to publish Now or Later'. If Later is chosen then gives the option of 'Please specify the Date & Time to publish' (either UTC or in a specific time zone)