스크린

<input type="text" placeholder="00:00" name="start_time" class="form-control">
@error('start_time') {{ $message }} @enderror
<input type="text" placeholder="00:00" name="end_time" class="form-control">
@error('end_time') {{ $message }} @enderror

검증

php artisan make:make:request TimeRequest

<?php

namespace App\Http\Requests;

use Illuminate\Foundation\Http\FormRequest;

class TimeRequest extends FormRequest
{
    /**
     * Determine if the user is authorized to make this request.
     *
     * @return bool
     */
    public function authorize()
    {
        return true;
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array
     */
    public function rules()
    {
        return [
            'start_time' => 'required|date_format:H:i|',
            'end_time' => 'required|date_format:H:i|after:start_time',
        ];
    }
}

<?php

namespace App\Http\Controllers;

use App\Http\Requests\TimeRequest;

class TekitoControllerextends Controller
{
    public function some(TimeRequest $request)
    {
        //バリデーション済み$requestが渡ってくる
    }
}