Use this code example to add a date format option in the Global Settings. This setting will be applied to the default date format for all date fields in your forms. Read more on the date formats using the jQuery datepicker and PHP date format.

Replace 'j M, Y' with the PHP date format. Replace 'd M, yy' with the jQuery date format.

add_filter('frm_datepicker_formats', 'add_custom_frm_format');
function add_custom_frm_format($formats) {
   $formats['j M, Y'] = 'd M, yy'; //change PHP and Datepicker formats
   return $formats;
}

For example, if you want to display the date format as Sat Mar 7, change line 3 to:

$formats['D M j'] = 'D M d';