The Order Ahead Days setting determines how many days in advance a customer can place an individual online order. It has no impact on catering orders.
The default setting for days ahead is 6 days, which means that customers can place orders up to 6 days in advance.
In order to make changes to this setting:
Go to Settings > General and scroll to Online Order Settings
Next to Order Ahead Days, select a number from the dropdown menu
Click on Update General Settings