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Ken Ward's Astrology Pages
Astrology: da Vinci (Julian Date)
| The purpose of this page is to point out that when
doing a chart for someone in the past, a lot of careful research may be needed to
determine the actual date of birth, or for other charts, the actual date.
For instance, Leonardo da Vinci was born on 15 April 1452, Florentine Calendar. Some say, at 9:40 pm. Based on his being born 3 hours into the night, with a 6:40 pm sunset. This is a Julian date. In the middle ages, the Florentine calendar was used in Italy. The new day began at sunset, not, as in our system, midnight. So someone born a few hours after sunset, would be born in the next day according to their recokoning, but for our reckoning, it would be the same day.
This means, therefore, that by our modern reckoning, that da Vinci was born on 14 April 1452, Julian Calendar.
Consequently, we take the following as his birth date in the old Julian Calendar: 14 April 1452 at 9:40pm.
This might suggest he was an Arian, but we must wait and see. We need to add 9 days to the date to turn it into our modern day Gregorian calendar. This means, in the Gregorian calendar, we have the date of birth as 23 April 1452 at 9:40 pm. The place was Vinci (10E55, 43N47). As I am going to use the Astrodienst tables, and I know they are in Julian for that year, the date will be kept to Julian (14 April 1452), because the conversions have already been done in the tables.
Calculate Greenwich Mean Time:
Now calculate the Greenwich Sidereal Time of birth:
Because there are no time zones, the local mean time is the time we have, or 9:40pm.
He was born at 20:56:20, GMT, so the proportion of the day was approximately 20.9/24, or 0.871.
Hence position is:
2º 47' 28"+50' 45"=
Or about 3ta38
12º07' x 0.871=10º34'
So the moon was 3pi02
Vinci (10E55, 43N47), sidereal time: 11:47:57
From tables for ascendant