Form Validation - Date Method

Value should be a valid date
diff --git a/system/language/english/form_validation_lang.php b/system/language/english/form_validation_lang.php
index 3bc4515..1230ce5 100644
--- a/system/language/english/form_validation_lang.php
+++ b/system/language/english/form_validation_lang.php
@@ -55,6 +55,7 @@
 $lang['form_validation_greater_than_equal_to']	= 'The {field} field must contain a number greater than or equal to {param}.';
 $lang['form_validation_between']		= 'The {field} field must contain a number between {param}.';
 $lang['form_validation_in']		= 'The {field} field must be within a predetermined list: {param}.';
+$lang['form_validation_date']		= 'The {field} field must be a proper date.';
 
 /* End of file form_validation_lang.php */
 /* Location: ./system/language/english/form_validation_lang.php */
\ No newline at end of file