<departureDate>200912</departureDate>

$year = $flightDates->departureDate->year;

// first two
$year = substr($flightDates->departureDate->year, 0, 2);
// last two
$year = substr($flightDates->departureDate->year, -2);

<?php
$someDate ='200912';
$dateObj = DateTime::createFromFormat('dmy', $someDate);
echo $dateObj->format('Y');
// prints "2012" .. (see date formats)

<?php

//$year = '200912';
$year = $flightDates->departureDate->year;

echo substr( $year, -2 );

?>

<?php

//$year = '200912';
$year = $flightDates->departureDate->year;

$date = DateTime::createFromFormat( 'dmy', $year );

echo date( "y", $date -> getTimestamp() );

?>

while ( $var > 100 )
{
    $var = (int) $var / 10;
}

$number = '<departureDate>200912</departureDate>' ;
$year = substr(strip_tags($number), 0,2);
var_dump($year);

$number = '<departureDate>200912</departureDate>' ;
$year = substr(simplexml_load_string($number),0,2);
var_dump($year);

string '20' (length=2)

byte[] array= Integer.toString(x).get.bytes().