In a production workbook (Excel 2002) I have the users enter the effective
date on a user form. I use the IsDate function to be sure it is valid. I
then place the date into a locked cell on a sheet. The IsDate function says
that 10/9/007 is a valid date. But on the sheet Excel treats it as a
string. So of course all calculations throughout turn to #ERROR. Does this
bug still exist in later versions?

Don <www.donwiss.com (e-mail link at home page bottom).