Maintaining 60+ avg speed all the way is not possible.
Speed may vary between 35/40 to 55/58 so make it 50 / 55 or even 48.
So if train leaves JMP at 5.00-05.15am and arrives HWH at 13:30 then chances of running late will be minimum.
In return it can leave HWH around 15:00 to arrive JMP at 22:30.