=IF(ISBLANK([@[Declaration Date]]),"", DATE(YEAR([@[Declaration Date]])+1,MONTH(3),DAY(31)))

I wrote the above to calculate the due date for new applications based on the declaration date on an event. The due date is always 3/31 in the calendar year following the year after the event, no matter what month/day.

The above formula is returning the correct year and day, but no matter what number I put after MONTH, the result is 1/31/XXXX rather than 3/31/XXXX. Excel not returning any error message on formula.

What did I do wrong?

Thanks.