best way to allow regular users to edit their posts within 15 minutes only

unlike admins, we want to grant regular users the chance to edit their posts within 15 minutes

what is the best place to put this restriction ?

if we use controller filters we must do it every were (in the post widget, in actionA and in actionB)

if we use validator then should it be limited for specific scenarios or for all scenarios but having a code like

if ( Yii::app() instanceof CWebApplication && ! Yii::app()->user->checkAccess('admin')) {



please advice for structure and best practice point of view,

thank you in advance,