Send email when publication period is chosen
When publishing a content object, if a publication period is chosen and you check 'send email', the sent email should reflect the chosen options with an appropriate message (e.g. 'on 01/01/2013, a new publication will be available' or 'the new publication will be available until 01/01/2013'. Also, the link provided within the email body should not be available if sent before or after the publication period.
Another possibility: let a program run (continuously) on the server and send the email automatically at the time of availability.