EOMONTH() returns the specific date of the end of the month for the specified DateTime.
Use EOMON() to return end of the month for the specified DateTime.
EOMON(D)
EOMON() returns the end of the month for the supplied DateTime. The end of month represents 23:59:59 on that day.
If the DateTime is invalid, then EOMON() returns an invalid date warning.
Acceptable dates are in the range January 1, 1900 to December 31, 9999.
Using a date of August 14, 2012:
EOMONTH(‘20120814‘) = ‘20120831 23:59:59‘