custom datetime class

AcmeDateTimeTest.php

<?php
namespace Acme;

class DateTimeTest extends \PHPUnit_Framework_TestCase
{
    /** @test */
    public function it_creates_from_unix_timestamp()
    {
        $unix = time();

        $acmeDate = new AcmeDateTime($unix);
        $standardDate = new \DateTime("@".$unix);

        $this->assertEquals($acmeDate, $standardDate);
    }

    /** @test */
    public function it_creates_from_datestring()
    {
        $dateString = '2016/03/03';

        $acmeDate = new AcmeDateTime($dateString);
        $standardDate = new \DateTime($dateString);

        $this->assertEquals($acmeDate, $standardDate);
    }
}

class AcmeDateTime extends \DateTime
{
    public function __construct($time = "now", DateTimeZone $timezone = null)
    {
        $time = is_numeric($time) ? "@" . $time : $time;
        parent::__construct($time, $timezone);
    }
}