To show Ground Advantage being delivered faster than Priority Mail is one of those times.
I have a new observation to share on this. It appears that part of the issue is the daily cut-off time being implemented differently for Parcel Select. Look at this -
This is the same package, shipping from Oregon to Florida. These screenprints are from 4 pm local time.
![image](https://sellersasksellers.com/uploads/default/original/2X/7/798a75c3add51b745a7c4e704c20d949476d99b1.png)
As expected, for first class and priority mail, when I make the ship date one day later, the estimated delivery date also becomes one day later. But it doesn’t for parcel select.
What seems to be happening is that Amazon is using a different shipping cut-off time for Parcel Select than for the other USPS services. In other words, it’s changing the ship date to ‘tomorrow’ (no matter what you input) earlier in the day than for other USPS services.
You probably realize that the system has a set time after which it assumes you are shipping “tomorrow” even if you tell it you are shipping “today”. Like you could purchase a USPS label at 11:55 pm with today as the ship date, but the system would treat that as going out on Friday, since Thursday would only have 5 minutes left.
For me, in Portland, OR, the system decides it becomes “tomorrow” at 5 pm local time. So, if I bought a first-class label at 4:59 pm today, the system might show me Mon, July 24 as the estimated delivery date, but if I waited and bought the label at 5:01 pm instead, the system would push the delivery date to Tues, July 25 because it would automatically assume I was shipping tomorrow instead. It’s the same as if I manually changed the ship date to Friday myself, only the ship date box would still show Thursday. But the system would be quoting you ‘as if’ you were shipping on Friday.
But since the delivery date for Parcel Select isn’t changing when I choose ‘tomorrow’ as the ship date, that tells me the system is already treating the time as “tomorrow” as far as Parcel Select goes. Which means that’s it’s using an earlier in the day cut-off time.
For purposes of first-class and priority mail, it becomes “tomorrow” at 5 pm local time, but I’m guessing that for parcel select, “tomorrow” comes at 2 pm.