Given the definition of Night shot (dawn/dusk/night) or shots with "long shadows", is there a practical cutoff to use for when to switch from night shot to normal?

I was shooting at LHR from the Renaissance from pre-dawn until about 8:30 AM, and while 8:30 (3+ hours after sunrise) would not be a night shot, the shadows are pretty long.

I've put them in the queue, so I'm not looking for pre-screening per se, but I don't want a bunch of rejections due to wrong/missing category so just want some advice there so I can make sure they're set correctly.

Example 1: http://www.jetphotos.net/viewqueued_b.php?id=4626415 shot early, shadow just a few degrees off horizontal.

Example 2: http://www.jetphotos.net/viewqueued_b.php?id=4626447 - shadow is still very long, but not quite horizontal anymore.

Example 3: http://www.jetphotos.net/viewqueued_b.php?id=4626459 - and lastly, still very long shadow but this is 2+ hours after...