I'm happy to have you as a member of the QuickBooks family and it's awesome that you've stumbled across the QuickBooks Community. It's a great resource to get answers to your questions and find how-to articles to get you going with tasks in QuickBooks Online. I'd be happy to help you out with this question about dates.
With more details about what dates you're looking at and where, I'm certain we can get you the answer to your question. I see you've posted it to the "Sales and customers" section of the QuickBooks Q&A forum, so I have an idea. I'm thinking you may be looking at the dates on your invoices or other sales forms when you create a new one through the +New button and are curious why the date isn't defaulting to today's date or the date you're expecting. I can explain.
When working with sales forms, they auto-populate certain information, such as the date and form number, both of which are based on the last sales form created. If the last form you created (whether an invoice or a sales receipt or some other sales transaction) was for a prior date, then the program will default the next date to that same day. For example, if I create a sales receipt today for November 16, the next form I create will also use that date.
The only time the form will use the next consecutive date is when the dates are in line with the current date. Using my example again, if I create a sales receipt today with today's date, tomorrow the program will use the 18th as the default date.
When the date isn't what you're expecting, it's a simple matter of changing it in the date field and you'll be good to go. There isn't a way to configure this setup or automation in your settings, but if it's something you'd like to have more control over, feel free to submit feedback about it using these steps: How do I submit feedback? Those comments are directed to the product development team for consideration in future updates.
If what I'm talking about here isn't what you're question is about, I invite you to reply with more information on this thread. That way, we can both be on the same page and I can let you know the options based on what you're looking at. I'm here to help!