Here is how to easily do what you want
1. Right click on the column header for pack_date and select Column Info
2. In the Column Info window, change the Data Type from Character to Numeric
3. Click on the down arrow for the format and go to Date and select "m/d/y"
4. Click on the down arrow for the Input Format and go to Date and select "y/m/d"
5. Click on OK
Jim