It departs Mo-Sa at 10:50 PM
for Cincinnati (ER #137), it returns at 6:48 AM
I see them loading it up and departing many times, when I was working in Downtown Newark for the State I would sometimes see it arriving (when it was late) on my commute into work in the Morning.
But if you never pass the airport past 10PM
or before 6AM your never going to notice it's been gone, the same for the ABX
used to have 3 DC-8s parked on the Fed Ex ramp all day, they would leave for Wilmington Ohio at night and return early the next morning.
I just got home from a Night in the City, it was there when I passed about an hour ago.