Hate to burst your bubble, but those times are almost guaranteed to be in local time.
So what you aren't seeing accounted is the two hours difference in time zones between the two cities.
edit: scratch that - at least, some of it.
Arizona doesn't observe DST, so right now they are.. three hours behind EDT?
That's more like it for time as well - westerly flights are often slower, and those are typically big ol' lumbering birds for parcel/freight delivery. Plus factor in the time between actually landing and that particular package getting scanned once in the sort facility.