Description - It can be helpful to determine how long a project (or task or issue) has been in a given status. The best example: On Hold.
Why is this feature important to you - If we can flag how long a project has been on hold, we can promote cleanup activities.
How would you like the feature to work - When configuring report filters, there would be an option to view the total amount of time the object has been in the status it's in right now. We would have the option to show this number by hours or days.