update application/admin/model/Field.php.

application/admin/model/Field.php

@@ -1111,6 +1111,7 @@ class Field extends Model
                     if ($v['form_type'] == 'checkbox') $default_value = $v['default_value'] ? explode(',', $v['default_value']) : [];
                 }
                 if ($v['field'] == 'order_date') {
+                }elseif($v['field'] == 'return_time') {
                     $default_value = date('Y-m-d', time());
                 }