Notice that the Met Office reported clear, but "night time" conditions
for 0800 GMT for London - despite the fact that according to
timeanddate.com, the sun rose at 0740. So where do they get the data
from? They don't seem to do the same at the other end of the day, e.g.
they've always shown "day time" conditions for 1600 GMT, even early in
this month.

Nick