Errr whats that last posting got to do with anything? FYI I very much doubt any passenger knows 'What time were due to be in the air' as you have no knowledge of expected taxy times or slot times. Most crew aim to leave the departure gate at the scheduled time of departure or earlier. If ATC wont let us go because of a slot delay or airfield congestion then there's not much we can do about it really. Anyway, in my experience 90% of delays departure delays are caused by SLF getting lost in the duty free shop!