'required|date', 'date_to' => 'required|date|after_or_equal:date_from', ]; } public function withValidator($validator) { $validator->after(function ($validator) { if (Carbon::parse($this->date_from)->diffInMonths(Carbon::parse($this->date_to)) > 3) { $validator->errors()->add('date_range', 'Date range exceeds 3 months. Please select a shorter period.'); } }); } }