DATEADD FUnction

Recently i have got a error in my application.
My application is based on banking. While payment happened in every month we need to move the next payment date to the next month.

Consider a scenario,

Payment Date is : 20th Aug

So if he pays for August then the Next payment date will be 20th Sep using the function in sql.

• DATEADD(M,1,date)

Now if a user is paying for the month of January, his current next date is

Payment Date: 30th Jan

Now we are adding the DateADD function.

DATEADD(M,1,'01/30/2012')  -----> Output will be 29th FEB(for Leap Year) and 28th FEB(Non Leap Years)

So all the dates will be wrong with the further Dateadd() function.