Date range changes from 2003 to 2007
 

In several charts created in Excel 2003 I had a 12 month date range as the X
axis, when opening these files in 2007 the X axis ranges have been changed to
days instead of months, this has also happened when using the day format
mm/dd ddd to represent a week such as 03/02 Sun through 03/09 Sun, when
opened in 2007 it changes the format to 3/2 and just shows a single day.