Hermetic astrologers mark the day by sunset, sunrise or midnight, and on 11th March 2004 in Madrid it was marked at sunrise being 07:36:51am, they use a margin or orb of four minutes or 1 degree.
They then mark out the position of Alnilam or Sirius by the four directions, in this case they used the Nadir, that is a straight line down from North in the Northern Hemisphere....Madrid is in the Northern Hemisphere, link to Nadir below:-
Nadir - Wikipedia, the free encyclopedia
On attachment please find two pictures, both at the same time, the first shows the Sun rising at 07:36:51, the second picture at the same time shows the Nadir cutting through the Belt of Orion/Osiris.
Please click on attachment astronomy pictures, when image comes up please click on image to make bigger.
Will continue in the next few days....getting the creeps yet?