Flight time from Dallas to etheopia?

A random search for flights from Dallas Fort Worth (DFW) to Addis Ababa (ADD) shows:

OPTION 1: 18hr 15min via Frankfurt (FRA)

DFW - FRA Lufthansa Flt 439 Dep 04:20pm 07May,Fri

FRA - ADD Lufthansa Flt 598 Dep 10:45am 08May,Sat

Flight Duration: 16hr 45min; Layover Time: 1hr 30min; Total Trip Time: 18hr 15min