Except the month of DEC-JAN, rest all throughout the year this train is the most trustworthy overnight train along with Lucknow mail in this region from LKO-DELHI.
During normal months, this arrives GZB before 06:00 am and NDLS by 06:30 am.
But during winters (dec-jan), this train sometimes gets late. And at that time its very risky if you have a link train from Delhi. Kindly keep a buffer of atleast 6-7 hrs.