That is slack time given for it to cater for delays.
If you will look at past one or two weeks performance then you will come to know. On many occasions it was lae by 1-2 hrs at Kanpur yet it managed to reach Ndls on time.
If you see yesterdays run, it was 1 h 30 mins late at Mgs, and yet its just 22 mins late now and will reach Ndls on time.