Formats changing to DATE without reason

[davidsosis]

I am working with several excel sheets. 50 percent of the time, when I reopen the sheet, all the cells are in DATE FORMAT. I have taken the entire workbook (12 sheets in workbook) and insured that no cells are dates. I formatted them as General or Percent. STILL, I just re-opened the workbook to make adjustments in data and found that it was back to Date Format.

Does anyone have an idea why this is happening? I've had two workbooks do this to me.

Please HELP!!!

 

[Peter_SSs]

I have just tried what Peter SSs suggested.

Which was what Andrew and Joe had already suggested.