how get 1th and 7th day of week in persian

1-7 new php.php

	/**
	 * ورودی تابع آبجکت DateTime  است
	 * خروجی این متد تاریخ اول و آخر هفته است
	 * اول هفته شنبه و آخر هفته جمعه
	 * خروجی نمونه 
	 * [
	 *   'from' => 2018-1-6, 
	 *   'to' => 2018-1-12
	 * ]
	 */
	public function getStartEndWeek($date = null)
	{
		if($date == null){
			$date = new \DateTime('today', new \DateTimezone("Asia/Tehran"));
			// $t = (new \DateTime('today'))->format('w');
		}

		$from = clone $date;
		$to = clone $date;
		$t = $date->format('w');
            
        if($t != 6 ) {
			//$t++;
			$interval = new \DateInterval('P'. ($t + 1) .'D');
            $from = ($from->sub($interval))->format('Y-m-d');
            //$from = (new \DateTime('today -'. $t .'day', new \DateTimezone("Asia/Tehran")))->format('Y-m-d');
            //$t = 6 - $t;
			$interval = new \DateInterval('P'. (5 - $t) .'D');
            $to = ($to->add($interval))->format('Y-m-d');
            //$to = (new \DateTime('today +'. $t .'day', new \DateTimezone("Asia/Tehran")))->format('Y-m-d');
        } else {
			$from = $from->format('Y-m-d');
			$interval = new \DateInterval('P6D');
            $to = ($to->add($interval))->format('Y-m-d');
            // $from = (new \DateTime('today', new \DateTimezone("Asia/Tehran")))->format('Y-m-d');
            // $to = (new \DateTime('today +6 day', new \DateTimezone("Asia/Tehran")))->format('Y-m-d');
		}

		return [
			'start' => $from,
			'end' => $to
		];
	}

1th_7th_day_in week_persian.php

<?php
$t = (new \DateTime('today'))->format('w');
      
if($t != 6 ) {
    $t++;
    $from = (new \DateTime('today -'. $t .'day', new \DateTimezone("Asia/Tehran")))->format('Y-m-d');
    $t = 6 - $t;
    $to = (new \DateTime('today +'. $t .'day', new \DateTimezone("Asia/Tehran")))->format('Y-m-d');
} else {
    $from = (new \DateTime('today', new \DateTimezone("Asia/Tehran")))->format('Y-m-d');
    $to = (new \DateTime('today +6 day', new \DateTimezone("Asia/Tehran")))->format('Y-m-d');
}

1th_7th_day_in week_persian2.php

<?php
$t = (new \DateTime('today'));
$f = new \DateTime('friday this week');

if ($t <= $f) {
    $from = (new \DateTime('friday this week -6 day', new \DateTimezone("Asia/Tehran")))->format('Y-m-d');
    $to = (new \DateTime('friday this week', new \DateTimezone("Asia/Tehran")))->format('Y-m-d');
} else {
    $from = (new \DateTime('friday next week -6 day', new \DateTimezone("Asia/Tehran")))->format('Y-m-d');
    $to = (new \DateTime('friday next week', new \DateTimezone("Asia/Tehran")))->format('Y-m-d');
}