In order to make this change, you will need to follow the below steps in your X3 application,

1. Log into the X3 reference folder
2. Go to Setup, General Parameters and then folders
3. Specify the folder you want to copy in the “Copy Folder” field
4. Enter the required field parameters
5. Set the desired start date
6. Save as a new name
7. Delete the previous folder

Once the above is done, the folder date is set.