I'm not arguing about what determines block out time. We use ACARS, when equipped.

But, when the ACARS time is obviously incorrect, they can and will, correct it. Have you ever had an ACARs initialize with the wrong current time? I've had them send times that were off by 15 hours. And guess what, they corrected them.

At FDX, if they haven't cleared you to push, ACARS shouldn't block you out.