In cell c11, enter a formula to reference the date stored in cell b7. insert a nested function in cell c12 to calculate the date for the next payment. nest the year, month, and day functions within the date function. add 1 to the month result. copy the function to the range c13: c34.

=B7 to be placed at c11. And the nested function at c12 is  

=DATE(YEAR(B7),MONTH(B7)+1,DAY(B7))

And to copy the function to the range c13:c34  copy c12 and drag the cursor to c34 and press enter. Each cell will then show the date with month incremented by 1 each time.

Explanation:

=B7 to be placed at c11. And the nested function at c12 is  

=DATE(YEAR(B7),MONTH(B7)+1,DAY(B7))

And to copy the function to the range c13:c34  copy c12 and drag the cursor to c34 and press enter. Each cell will then show the date with month incremented by 1 each time.

Remember, for nesting date function, we need to provide the arguments year, month and day to the date function. Year at B7 is YEAR(B7), Month is MONTH(B7), Day is DAY(B7). And we need to increment the Month by 1. And thus the above formula.

For referencing to another cell which is B7, we need to write =B7 at c11.