all cells in 2 workbooks have automaticlly changed to date format

[dloc]

Why would excel 2007 automaticly change formats?

Upon opening a workbook this morning all the blank cells in the 16 sheets
had changed from general format to date format, and 99.9% of cells with data
or formulas were also changed to the date format.
I opened another workbook and it was find, I closed it and reopened it and
the same thing occurred, most cells had been changed to the date format.
The first wb containts payroll data, with mostly sumifs functions and was
working fine yesturday. The second wb contains data using vlookup and if
functions.

Thank you
Deb

 

[dloc]

Found the answer here

(Msg. 6) Posted: Wed Jan 28, 2009 12:31 pm
Post subject: RE: Excel 2007 Cell Format Change Bug Warning [Login to view
extended thread Info.]
Archived from groups: microsoft>public>excel>crashesgpfs (more info?)

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Started seeing this 2 days ago on large spreadsheets with 10-20 tabs > 15MB.
It added a custom format that looked like this "[$-409]d-mmm-yyyy h:mm
AM/PM;@" No idea how it got there. I fixed it by deleting that particular
format and cells went back to General format.


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