Closing doors 1 minute after Schedule time is considered late, and a delay code must be assigned. And then, another check between Schedule and Actual T/O time (again, even a single minute is considered as a delay)
Well, pushback would occur a few minutes after that. This is what every airline I've ever dealt with uses as the ATD.
I assume you meant if the ATD is 1 minute later than scheduled (whether you use doors closed/pushback, brake release or whatever), then a delay code should be assigned. Well, technically, yes. However lets think about it; you describe a delay potentially as small as 1 second (ie for a 1235 STD: The difference between 12.35:59 (on time) and 12.36:00 (one minute late)), which I'm sure that even the most hard-assed ops agent wouldn't give a stuff about.
Its all about using your common sense, taking the hit when you've messed up, and not blaming anyone else when it isn't their fault. As mentioned above an agreement is made a lot of the time between ground and flight crews as to whether a flight is 'on-time' given a short delay.
And then, another check between Schedule and Actual T/O time
Really? No airline I've seen has given a 'Scheduled Take-off Time'. Taxi time at both ends is all taken into account in the time between the STD (pushback) and STA (on stand/chocks etc). The variability of taxi times at a large airport would make giving a 'scheduled take off time' nigh on impossible.
Not so good as it was at my station. Airport management has started requesting the registration/fltno of the aircraft causing the 'blockage', and preventing our aircraft from pushing.
Too many people with not enough to do? Sounds about right eh?