Far too often "Scheduled Delivery Today" is a nice notion, but not a fact with regard to correct tracking status. Even "On Vehicle for Delivery Today" may not mean it will make it off of that vehicle today. Here in the Pacific Northwest anything that says your package is in Troutdale Oregon (suburb of Portland) really means that it will be delayed another day or two, that is if it didn't just go there to die.
It is a daily competition between USPS, UPS, and FedEx as to which service I have the greatest distain.