you would need to edit the query created for the chart and use the MySQL Date_FORMAT command.
in the DynamicWebCharts/Data folder a file will be created named <pageName>_data1.php where <pageName> is the name of the page you applied the chart to.
this file has the recordset.
edit the recordset and add the DATE_FORMAT function around the date column:
DATE_FORMAT(dateColumn, '%d/%m/%Y')