Had it been travelled via Patna it won't have cross Jhajha before 1800,because there is an official block in Main line b/w Jasidih Madhupur everyday from 1200-1800 Hrs right after Patna Dhanbad & Poorva crosses.Now Poorva never manages to cross on time so it always departs after the block & reaches HWH after midnight.Whereas in Grand Chord there is no such obstruction & Grand Chord has much higher avg speed & very less congestion compared to Main Line