I have contacted the theme author and asked for him to make a change in the sky functionality plugin.
In file lib/functions/geodirectory.php around line 1475 these lines need to be added:
// check if we need to change the format or not
if(function_exists(‘geodir_date_format_php_to_jqueryui’)){
$extra_fields[‘date_format’] = geodir_date_format_php_to_jqueryui($extra_fields[‘date_format’]);
}