ARM Transaction upload date format

We are currently on 11.1.2.3.500 and when end user's upload transactions into ARM, the only date format that is accepted by ARM is this format:

mmm dd, yyyy

i.e. Jul 31, 2014

Here is the problem our users are encountering with this, after exporting their transactions from ARM as "Unformatted data for future import", a CSV file is saved to their machine.  When the user right-clicks on the CSV file and selects to Open With Excel, the file opens in Excel.  BUT, the dates in Excel have now been updated to something other than the format accepted by ARM (I'm thinking this is some setting in Excel somewhere).  So after they add their additional transactions to the file (mimicking the same date format shown), save the file as CSV and attempt to