my question related to sqlserver date functioan

Question

sir i making property website so...first we sale plot ,,plot is sale full payment and laon....

one plot is cost 10000 any person want to by this plot by loan...so we take money ..through (EMI) 

.......................................................LIKE THIS...............

CUSTOMER NAME..............................ANUJ

CUSTOMER ID......................................1

CUSTOMER GIVE AMOUNT ...............10000....

CUSTOMER FIRST EMI DATE..............(6-11-2015)

..............................................................................................

NOW WE WANT NEXT MONTH DUE EMI DATE..

 

BUT PROBLEM IS MONTH DAYS ..SOME MONTH IS 30 DAYS SOME 31 AND FEB IS 28 OR 29

SHO HOW CAN CALCULATE DUE EMI DATE FOR NEXT MONTH..

 

 

I USING ASP,NET AND SQL SERVER   AND C# LANGUAGE.