12873 needs revisiion in it's timetable ... today when I had tracked that train it was 1 hr 5 mins before at GZB. So considering this a lot of time can be saved from this.
Also, it is seen that when 12873 can cover a distance between CNB and ANVT in 4.5 hrs or 5 hrs ( when it is delayed and even on regular days) , the train is delayed purposely.