How long does it take to fly from Edmonton to Athens?

A random search for flights from Edmonton (YEG) to Athens (ATH) shows:

OPTION 1: 15hr 20min via London Heathrow (LHR)
YEG - LHR Air Canada Flt 898 Dep 05:50pm 18Dec,Fri
LHR - ATH British Airways Flt 632 Dep 12:25pm 19Dec,Sat
Flight Duration: 12hr 30min; Layover Time: 2hr 50min; Total Trip Time: 15hr 20min