Inserting current publication date into a topic

We want to add the current month and year that a publication is published in our copyright topic.  This would be the month and year that an author clicks Publish in Publication Manager to publish their output.  This copyright topic is library topic that is reused in several maps/publications.   

 

Is there a way to set up a variable that SDL would then automatically populate with the Published current month and year?  It would seem like SDL would have a system variable that I could use for this purpose?