1. When you say not opened do you mean not updated? 2. if yes, you can use the last modified date and write a formula field to give true if the last modified date is in the respective range of days and use the formula field as a filter in the list view.
1. When you say not opened do you mean not updated?
2. if yes, you can use the last modified date and write a formula field to give true if the last modified date is in the respective range of days and use the formula field as a filter in the list view.
Hope it helps
RD