Carbon_demo_Class.php

<?php

use Carbon\Carbon;

class TimeCounter
{
  protected $startTime;
  protected $endTime;
  
  public function start() {
    $this->startTime = Carbon::now();
  }
  
  public function end() {
    $this->endTime = Carbon::now();
  }
  
  public function duration() {
    return $this->startTime->diffInMinutes($this->endTime);
  }
}