!!! Overview
[{$pagename}] is the interval of time that the [entity] is valid.

Typically there would need to be a [timestamp] for the start of the [{$pagename}] and thus the expiration is [timestamp] + [{$pagename}] 

!! More Information
There might be more information for this subject on one of the following:
[{ReferringPagesPlugin before='*' after='\n' }]