Long Shot

I wasn't going to sleep in a hurry. The the thermometer read -9 and road outside was sufficiently icy to put off much of the overnight traffic.
I fancied trying yesterdays long exposure again, even though in reality this was taken not long after midnight. Setting up in front of the bedroom window. I let the camera go for 45 minutes as I watched a film in bed.
I know the red splurge could have been avoided by opening the window but I couldn't bear the cold, however, I'm amazed at how much detail I've caught from a scene that was entirely black. It's far from perfect but I'm pleased with the result.

I really have little wish to go out this morning, but I have to go and put some things in order before I travel. The dogs deserve a good walk too. I think it's a case of pulling out the thermals... boy is it cold out there!

Question... Does the date and time of a photograph register when the shutter opens or when it closes?