<?=Yii::$app->formatter->asRelativeTime($model->created_at);?>

必须在common\config\mian.php里面设置：

'language' => 'zh-CN',
'timeZone' => 'Asia/Shanghai',
'components' => [ 'formatter' => [ 'dateFormat' => 'yyyy-MM-dd', 'datetimeFormat' => 'yyyy-MM-dd HH:mm:ss', 'decimalSeparator' => ',', 'thousandSeparator' => ' ', 'currencyCode' => 'CNY', ], ],

切记，数据是后台传过来的。前端从数据库中获取然后foreach输出即可