eomdate
(Not recommended; use dateshift) Last date of
            month
eomdate is not recommended. Use the
                dateshift function instead because it accepts
                datetime values as inputs. For more information on updating your
            code, see Version History or Replace Discouraged Instances of Serial Date Numbers and Date Strings.
Description
                returns the serial date number of the last date of the month for the given year and
                month. However, if DayMonth = eomdate(Year,Month,outputType)outputType is "datetime",
                then DayMonth is a datetime array. By
                default, outputType is "datenum".