OTD is pushback or release or a/c brakes, Screens show actual take off times. There is therefore always difference between the two as there is variable waiting times at the holding point. So if you look at the screen info only nearly all flights of all airlines at city look late. Obviously with a 25 min turnaround including a clean of a/c unless you arrive early you never get out ontime however like all airlines extra sector time is built into schedule to accommodate this and then most flights arrive within the 15 min industry standard of an ontime arrival.