Problem Comparing With Date Format

Hi veryone , I show the dates on my gridviews like d-m-y and when I’m gonna use the search, it doesn’t work obviously because when yii compare one date is formated like Y-m-d(model) and in the gridView is like d-m-Y so I tried to fix it changing on the model the compare instruction in function search like :

//instead of this:


//I used this.


But this doen’t work, can anyone help me??