custom validation

i m not getting custom validation ,i read yii2 custom validation from documentation and from reference guide,but still confuse

how this code will work

like i have to field start_date and end_date

i want when user select date from calender then it will check user subscription period ,so i need show error when user select date befor or after of subscription date

user selecting start_date 2014-01-02 and end date 2014-05-02

if user selcting date in any form where i have datepicker it will check user subscription date if it is lying between then ok otherwise gives error.

my code

in model rules

[start_date,valideStart_date],

[end_date,valideEnd_date],

public function valideStart_date($attributes,$params){

   here just check if select date is bigger then start_date then it is ok

otherwise gives error

}

same for end date

how to do this

How do you do which bit? It looks like you have the correct idea, what can’t you do?

Anyway, here is a link to how to use "custom" validation with an example:

http://www.yiiframework.com/doc-2.0/guide-input-validation.html#inline-validators