php__silex__book/src/demo/Services/Timer.php

<?php

namespace demo\Services;


class Timer {
  const SCALE = 1E4;

  protected $t0;

  protected function __construct($t0) {
    $this->t0 = $t0;
  }

  public static function create() {
    return new static(microtime(true));
  }

  public function delay() {
    $diff = microtime(true) - $this->t0;
    return round($diff * static::SCALE);
  }
}