How to convert an HeathKit NSDate time format to a Unix Timestamp for PHP

nsdate.php

<?php
// This will convert a iOS HealthKit Data Export startDate or endDate (NSDate format)
// into a DateTime Object for use in PHP
// Written by Chris Kacerguis

$nsdate = '20150802105200-0500';
$format = 'YmdHis-O';
$objDateTime = DateTime::createFromFormat('YmdHis', (int) $time);
$human_readable = $objDateTime->format('F d, Y h:ia');
$unix_timestamp = $objDateTime->format('U');