Returns the date of the last day of a month.
addmonths is a number of months to be added to the startdate (given as text or a date-time serial number), to give a new date. For this new date, EOMONTH returns the date of the last day of the month, as a date-time serial number. addmonths may be positive (in the future), zero or negative (in the past).
returns 39507, which may be formatted as 29 Feb 08. 2008 is a leap year.
where cell A1 contains the date 16 Dec 07, again returns 39507, which may be formatted as 29 Feb 08.