Trait to map validated dates from Laravel FormRequest to Carbon instances

TransformValidatedDates.php

<?php

namespace App\Traits;

use Illuminate\Support\Arr;
use Illuminate\Support\Str;
use Illuminate\Support\Carbon;

trait TransformValidatedDates
{
    public function validated()
    {
        $dateFormatMap = $this->fieldsToMapWithDateFormat();

        return collect(parent::validated())->map(function ($value, $field) use ($dateFormatMap) {

            $fieldWithDateFormat = $dateFormatMap->get($field);

            if (is_null($fieldWithDateFormat)) {
                return $value;
            }

            return $fieldWithDateFormat
                ? Carbon::createFromFormat($fieldWithDateFormat, $value)->startOfDay()
                : Carbon::parse($value);
        })->all();
    }

    private function fieldsToMapWithDateFormat()
    {
    	return collect($this->validator->getRules())->map(function ($rules) {

            $daterule = Arr::first($rules, function($rule) {
                return is_string($rule) && 
                    $rule == 'date' || Str::startsWith($rule, 'date_format:');
            });

            return $daterule
                ? explode(':', $daterule)[1] ?? ''
                : null;

        })->reject(function ($dateformat) {
            return is_null($dateformat);
        });
    }
}