How do I make custom due dates? I used to be able to choose a different date instead of the default terms but Quickbooks no longer allows me to.

It’s nice to see you in the Community space, @hycouture.

Due dates are all dependent on the Terms set on a transaction. You can create one by going to All Lists from the Gear icon. 

Here’s how:

1. From the Lists page, select Terms.
2. Click the green New button at the top.
3. Enter the Name of the term and choose the right option.
4. Hit Save to complete the process.

Then, assign a default term to your customers or suppliers. Follow the steps below:

Customers:

1. From the Customers page, choose a customer.
2. Click the Edit button at the top.
3. Pick the Payment and billing tab.
4. Select a term on the Terms drop-down box.
5. Hit Save. 

Suppliers:

1. From the Suppliers page, select a supplier.
2. Click the Edit button at the top.
3. On the Supplier Information window, assign a term for this supplier by clicking the Terms drop-down box.
4. Hit Save.

Take a look at this article for more details: Set up payment terms. While the article is designed for QBDT, much of the information is relevant for QBO. 

Post in the Community again if you have any questions. I’m more than happy to help. Have a pleasant day ahead!