Hi there, @colin29.

Thank you for reaching out to us. It's my pleasure to assist you today. 

Do you need to add a new column to the invoice table? Currently, we can only add custom fields in the Header section of the invoice form. However, if you want to change QTY to Hours instead, you can accomplish it by editing the label.

Here's how:

1. Go to the Gear icon, then Custom Form Styles.
2. Click New Style and choose Invoice.
3. Enter a name in the Name field.
4. Select the Content tab and then click the middle section of the form.
5. Click Edit Labels and Widths.
   
6. Edit the QTY field to Hours/Hrs.
7. Hit Done.

If you use QuickBooks Time and start approving billable entries, ensure to choose the template when invoicing it. This way, you'll have the correct label for hours when printing or emailing it to your client.

Here's how:

1. Click +New and then Invoice.
2. Choose the customer's name. This opens the Add to invoice window.
3. Click Add on the billable time you want to charge to your customer.
4. Select the Customize button and pick the template you created.
   
5. Choose Save and close.

This is what it'll look like when printing it:

Furthermore, you have the option to set up custom fields in QuickBooks Time. It allows you to track extra details on timesheets, then assign them to jobs/customers.

Please let me know how these steps help you achieve your goal or if you're referring to something else. I'm determined to ensure to provide the assistance you need. Have a wonderful day!