I order a ton of stuff on the internet and typically my UPS tracking says "out for delivery" within 45 minutes on either side of 5 AM and gets to me between 10 am and 2 pm but I live in a major city with probably several hundred UPS trucks and routes servicing the area (DC, big government stuff).
So this shouldn't be considered predictive but they are always consistently within that 4 hour window for me.