Allah the Almighty is the one who alone knows the knowledge of the Unseen. Any person who claims to know what has been hidden from us through horoscope, palmistry, numerology, or the like means actually claims to share this knowledge with Allah, which contradicts the very basics of Muslim’s belief.
Accordingly, reading one’s birth date with the aim of revealing the unknown and disclosing the unseen future is typically equal to palmistry and numerology, and thus it is absolutely prohibited.