EOMONTH (start_date,months)
EOMONTH returns the last day of the month which is @months from the @start_date.
Returns #NUM! if start_date or months are invalid.
This function is Excel compatible.
If A1 contains 12/21/00 then EOMONTH(A1,0)=12/31/00, EOMONTH(A1,5)=5/31/01, and EOMONTH(A1,2)=2/28/01
MONTH.