$re = '/(?P<YEAR>[\d]{4})-(?P<MONTH>([0][1-9])|([1][0-2]))-(?P<DAY>([0][1-9])|([12][0-9])|([3][01]))T(?P<HOUR>([01][0-9])|([2][0-3])):(?P<MINUTES>([0-5][0-9])):(?P<SECONDS>([0-5][0-9])).(?P<MILLIS>[0-9]{3})Z/';
$str = '<Id>2016-06-29T17:03:37.000Z</Id>
<Lap StartTime="2016-06-29T17:03:37.000Z">
<TotalTimeSeconds>6906</TotalTimeSeconds>
<DistanceMeters>60870.5</DistanceMeters>
<Intensity>Active</Intensity>
<TriggerMethod>Manual</TriggerMethod>
<Track>
<Trackpoint>
<Time>2016-06-29T17:03:37.000Z</Time>';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php