dec2015010011.jpg dec2015010010.jpg dec2015010009.jpg dec2015010008.jpg
Ref
Astro-Databank gives the proposal of seven astrologers and the favored year of Buddha's birth is 623 BC which is also the year adopted by the Buddha Dharma Education Association and UNESCO.
 
Legend has it that Siddhartha's father was a King of the sun worshipping clan Shakyas of late Vedic India (c.1100-c.500BCE) and they lived in a palace in Kapilavatthu (destroyed in the 4th Century ADlocated 10 km west of Lumbini where Siddhartha was born.
 
 
Vesak is the day celebrated as the Buddha's birthday but its actual date varies across Asian countries with the general agreement that it is on a Full Moon. The Astro-Databank has a number of proposals being in April which would make his Sun sign Aries but to my mind Aries does not have the same inclination for sitting as does Taurus.
 
In 623 BC the Full Moon in May was on Friday the 15th with midday coinciding with a Leo Ascendant which would agree with the Buddha's ability to lead others.
A birthchart for this time is given below and notably has Neptune in the 6th house of daily service to others, square Uranus in the 3rd which means his way of communicating may not have been in line with his need to be of service; with the 9th house stellium of  Venus, Eris, Mars and Mercury all completing the 'T' square with Uranus and Neptune.
 
Siddhartha would be totally confused about how to find a resolution that would provide him with a peace that reconciled the outer world with the idealistic life he had led up to his astrological maturity on his Saturn Return at age 29. Especially since his birth chart Full Moon puts the Sun of self development opposite his Moon of personal emotion - with the Sun being in the most powerful position of public life (on the MC) while his Moon is on the innermost point of self-reflection (on the IC).
Siddhartha left the palace at age 29 which would corresponds with his Saturn Return (on the 9th cusp) at which time Neptune is transiting natal Jupiter, Jupiter trine natal Neptune, Uranus trine natal Uranus and sextile Mars, the North Node conjunct Uranus, Ceres on the Ascendant and  Sun conjunct Pluto:
Siddhartha achieved enlightenment at age 35 and the importance of his solar return of that year is magnified due to its conjunction with the MC. Here's his solar return in 588 BC overlaying his proposed natal chart. 
Note the powerful indicators of enlightenment that this solar return for that year implies:
 
Pluto transiting conjunct Venus in the 9th house, activating the Uranus/Neptune/Venus T square and heralding a breakthrough in Siddhartha's understanding of relatedness.
 
Uranus transiting conjunct 8th house Pluto with Saturn transiting square and  providing insight and change in his understanding of the material orientation of the world around him.
 
Neptune and Venus straddling natal Saturn on the 9th house cusp emphasising empathy and relatedness as being the most important focus of daily practical perfunctory routines (Saturn ruling the 6th house and Neptune occupying the 6th).

According to Buddhist teachings the basis of happiness is our attentiveness to thoughts and actions and the resulting cultivation of wisdom and compassion. This seems to be the goal of all the sages through time who have come to this conclusion through various pathways corresponding to totally different planetary arrangements which gives the promise of any person being able to achieve this enlightenment if they put their mind to it.

 

Siddhartha's proposed birth chart aligns with his life as we know it and the process of his enlightenment is clearly spelt out in the movement of the planets from that point onwards.

 
 

Conclusion
Rectification of Midday Birth
Since Siddhartha's enlightenment is such an important event, solar arcs should verify this date so here's his solar arc for 14th May 588 BC overlaying his birth chart, and as you can see Pluto is opposite natal Uranus and square Neptune – the T square which is at the heart of Siddhartha’s search for perfect relatedness. With his awakening channeled through his meditation represented by Mercury conjunct North Node and Jupiter conjunct Mercury. The Ascendant’s Solar Arc is almost opposite natal Pluto and most importantly Saturn is almost conjunct the MC. My understanding would have his Saturn right on his MC and this would be the case if he were actually born closer to 12.03pm.
'Whatever he tried, Siddhartha could not reach the level of insight he sought, until one day when a young girl offered him a bowl of rice. As he accepted it, he suddenly realized that corporeal austerity was not the means to achieve inner liberation'...About 100 miles away, he came across the five ascetics he had practiced with for so long, who had abandoned him on the eve of his enlightenment. Siddhartha encouraged them to follow a path of balance instead of one characterized by either aesthetic extremism or sensuous indulgence. He called this path the Middle Way.'
Siddhartha (Buddha) Gautama Birth Chart