The increased push by Amazon and by the customers to have their parcels arrive by the delivery date promised has the carriers all working to try and meet those schedules. With the delivery guarantees offered by the carriers for some of the services they offer and the extended days for delivery, failing to meet the date and time promised can result in complaints and customer demands to Amazon for a refund of shipping costs. There are also external and unexpected delays which might impact the day's delivery schedule, including equipment breakdown, unavailable drivers, weather, and increased volume in parcels.
Tomorrow BY 8:00 PM, not at. At 8:00 PM the delivery drivers will be home watching Jeopardy.
Amazon doesn't actually deliver anything. Deliveries are handled by FedEx, UPS and other delivery services. You can call and ask them what time they anticipate the delivery, but most won't say because it depends upon the exact route the driver takes and traffic, among other issues.
It says BY 8 pm - not AT 8 pm.
