yes , the problem is not the width, once I open the same exact document in 2010 or 2013 and I use the formula it returned #

in the worksheet, the person is supposed to write the year so the formula works by changing the days of the months but as I said it won't work on those excels. Actually, once I open it on 2010 or 2013 and go back to open it on 2007 it stops working in 2007 too.