Start and expiration dates attached to content. Not playlist, widget or container

Hi are there any plans to add a start date to the individual media content files? This work work in the same way a s the expiry date feature.

This would be very useful when using the dynamic content features, meaning you could use 1 tag across multiple site individual playlists and pre load the media in advance of the start date so that it would follow on once another piece of media has expired. Example of use, convenience stores 3 weekly ever changing product promotions.

Many thanks

Jason