If you have overdue invoices or bills in Float, they will show as payable today. So you'll need to update their expected payment dates.
In your Invoices Due and Bills to Pay tabs in Float, you can see a list of your upcoming bills and invoices. You will see an 'Original Due Date' and an 'Expected Date' for each item, like this:
The original due date comes from your accounting software, but you can change your expected payment date on any bill or invoice.
To do that, select the items you'd like to update, and then click 'Batch actions' in the top left:
You can choose a set date, or a number of days from the due date.
Once you have updated your expected dates, these will move forward in your cash flow forecast.