Is it a common problem to see due date on an invoice not calculate correctly using terms and invoice date? Invoice due dates often incorrectly auto fill with end of month

Hey @lindak1119,

Nice to have you in the Community. I'm here to lend a hand with terms calculating not calculating correctly on your invoices. 

QuickBooks Online offers the ability to customize terms, such as specifying a set number of days or time of the month that the invoice is due. Since you've referenced that it will autofill to the end of the month, it sounds like the terms may have been customized. Here's how you can view and edit the terms:

1. Select the Gear icon.
2. Click All Lists.
3. Choose Terms.
4. Select the triangle drop-down under the Action column and click Edit.
5. Verify that the Term is properly configured.
6. Select Save.

The following is a brief video to serve as a visual reference:

I recommend viewing the following post that @196578 produced which covers this in more depth, such as why terms should be adjusted: How to Adjust Invoice Payment Terms in QuickBooks Online.

That's it. I'm confident that in a few clicks your invoices will have the correct due dates. 

As always, I'm just a post away if you should have any questions. Wishing you a pleasant remainder of the week.