Converting XML data about health rate from Apple Watch to CSV

gistfile1.php

<?php

$xml = xml_parser_create();
xml_parse_into_struct($xml, file_get_contents("export.xml"),$values,$indexes);

print '"Date/Time","Average","Minimum","Maximum"'."\r\n";
foreach($values as $val) {

  if (isset($val["attributes"]) == false) {
    continue;
  }

  if ($val["attributes"]["TYPE"] != "HKQuantityTypeIdentifierHeartRate") continue;

  $date = $val["attributes"]["STARTDATE"];
  sscanf($date, "%04s%02s%02s%02s%02s%02s-0400", $year, $month, $day, $hour, $minute, $second );
  $readable_date = $year."-".$month."-".$day." ".$hour.":".$minute.":".$second;
  $min = round($val["attributes"]["MIN"] * 60);
  $max = round($val["attributes"]["MAX"] * 60);
  $avg = round($val["attributes"]["AVERAGE"] * 60);

  print '"'.$readable_date.'","'.$min.'","'.$avg.'","'.$max.'"'."\r\n";
}