If u add full dob then ur destiny no. arrives.for example if someone is born on 24/6/1977.his destiny no. will be 9.(2+4+6+1+9+7+7=9).read the comments to know about the destiny no. 9 here. 
 

 Destiny No 9 signifies Humanitarianism.  
People wth this no. tend to be self sacrificing. 
They easily fall prey to others' needs and are taken advantage of. Sensitive, caring Nines are romantics at heart and may get deeply wounded in case they meet with failure in love. 
Their humanitarian aims have a universal approach. On the downside, many nines end up being just the opposite in life and run the risk of becoming too selfish.