=DATE(YEAR(A1),MONTH(A1)+1,0)

and copy down

--
HTH

Bob

(there's no email, no snail mail, but somewhere should be gmail in my addy)

"JPS" wrote in message
...
I have a spreadsheet with 1000+ rows and I need to correct a date column,
This column should contain the last day of the month, but often does not.

I am in need of a formula that will check the month and correct to the
last
calendar day, i.e. November would be 30 and December would be 31. I need
to
retain the original month and year and correct only the day.

Thanks.

--
JPS