Change in date of birth

I am a final year student doing ec engg. I have different date of birth in my SSc marksheet and Transfer Certificate. In SSc marksheet its 25/05/1991 and in Transfer certificate its 27/05/1991. I am from CBSE board. My original date of birth is 27/05/1991. I have to go for SSB interview in Air Force in November. Please give me advice what should i do now to get the same date of birth in both the documents.