If you've added content to the Editable Content block Admin.EditableContent.Name.DeliveryModuleBottom then you will need to enable Show Order Delivery Date in OPC in Delivery / Shipping Settings, however you may not wish to show the delivery date predictor.
If you'd like to hide this, then you will need to add the below snippet to the same Editable Content block:
<style>
.deliveryModuleContainer {
display: none;
}
</style>
This will hide the predictor at checkout.