added created_at

app/controllers/application_controller.rb

@@ -36,6 +36,7 @@ class ApplicationController < ActionController::Base
     str = "controller=#{self.class} action=#{self.action_name} "
     if current_user
       str << "uid=#{current_user.id}"
+      str << "created_at=#{current_user.created_at.to_date.to_s}" if current_user.created_at
     else
       str << 'uid=nil'
     end