add 15 days to date in loop php

<?php
  // adding extra days to date 
  
  // Steps:
	// 1) using carbon
    // 2) using strtotime
      
    //Step 1
  $date = date('Y M d h:i:s') // 2020 09 22 22:09:26 UTC
  
  $new_date = Carbon::parse($date->addDays(1); // adds extra day
                            
  // Step 2
  $date = date('Y M d h:i:s') // 2020 09 22 22:09:26 UTC
  
  echo $new_date = date('Y M d h:i:s', strtotime($date. '+1 day'));
?>$begin = new DateTime('2010-05-01');
$end = new DateTime('2010-05-10');

$interval = DateInterval::createFromDateString('1 day');
$period = new DatePeriod($begin, $interval, $end);

foreach ($period as $dt) {
    echo $dt->format("l Y-m-d H:i:s\n");
}
$begin = new DateTime( "2015-07-03" );
$end   = new DateTime( "2015-07-09" );

for($i = $begin; $i <= $end; $i->modify('+1 day')){
    echo $i->format("Y-m-d");
}echo date('d/m/Y',strtotime('+30 days',strtotime(str_replace('/', '-', '05/06/2016')))) . PHP_EOL;