Make the check that Dave Peterson recommended.

Can you manually change the data back to the correct types? If you can,
then you can first choose all cells and change their data type to General and
begin the tedious task of changing what you currently have to the proper data
types. You haven't actually lost your data, just the way it appears, so
changing the format will get things back to the way you need them to be.

"Eddie" wrote:

I am using Excel 2007. I have a worksheet filled up with some number,
currency and date. It was working fine all this while. Just recently, when I
open that file. All the cells format change to date format. This is included
blank columns or rows. Its screw up all the data...

May I know why is it happen and how to rescue my file?

Thank you
Eddie