N        This expression is nonsense and always returns 0, regardless of parameter.


The parameter was tested with

  • blank ""
  • file name
  • file path
  • URL
  • cookie name

And none of them apply. There is a Last-Modified response header, but that's not given in a request.


Unix timestamps are number of seconds since January 1st 1970 00:00:00.

You can read the current Unix timestamp using the Timestamp object's expression, and do timestamp adjustments with that extension.