Golf Game Spreadsheet

I have a Golf Game done in a spreadsheet but there is some errors that need to be fixed in the VBA code. The main problem is that the dates are formatted for US date format mm//dd//yy but here in Australia we use dd//mm/yy. The program then cant distinguish dates properly ie 1/4/12 - the program cant tell if it is supposed to be 1st April or 4th January. But what it seems to do is use dd/mm/yy (default??) until the day reaches 13, then it uses mm/dd/yy as it then realizes that there is only 12 months of the year and can now determine a date format. I need it to read Australian date format - dd/mm/yy. Further details will be sent.