How to validate date field in Laravel

I am doing laravel project and for that I want to validate start date and end date. Start date should be after today and end date can be start date or after start date.Following is my validation code,

        'start_date' => 'required|date|after:today',
        'end_date' => 'required|date|after:start_date',

From that I am getting end date as after start date but I also want as end date can be start date. How should I do this?

via Chebli Mohamed