When our team is working on tickets, it would be nice to have a drop-down available that can show tickets that have not been updated in {X} days.  This is useful when we are trying to work through a backlog for the day, and the tickets disappear off the list, as we respond back to them.  

Currently, we are using the Custom field to enter the dates, but when we save the filter, we are always having to change the dates.