Also, if you are operating the first inbound flight of the morning, then you are at the mercy of when the transatlantic and far east traffic decides to turn up. If this is late, then it tends to get caught up with the short haul traffic which appears about 7am local and thus can cause delays.
On the last set of nights, the trans-atlantic stuff was about half hour late because of a weak jet stream and some of the flights who are authorised to land before 6 local were also late from the far east which meant 15-20 minute delays at 6.30 in the morning.
A good start to the day!!