GQ 21 then GQ 430 at Athens
Syros → Athens → Skiathos
Timetable, Athens time
13:40GQ 21 from Syros at the gate
13:30GQ 430 to Skiathos leaves the gate
23 h 50 apart on the timetable, overnight
GQ 430 leaves 23 h 50 after GQ 21 arrives on the timetable: more than half a day, so not a connection we count.