trains in & out of delhi in the morning & evening are sure to get delayed....i often have to travel to allahabad for work & the airport there is not equipped to handle fog season so ai cancels its flight there almost every day during this period....i've often had to take the train to allahabad & back....on an average, the trains are delayed by about 8 hours....the longest delay i remember was almost 20 hours a couple of years ago....