- date_default_timezone_set: documentation ( source)
<?php date_default_timezone_set('Europe/London');
$format = 'Y-m-d H:i e';
$times = array(
'2015-10-24 15:00:00 01:00:00 BST',
'2015-10-25 15:00:00 01:00:00 BST',
'2015-10-26 15:00:00 01:00:00 BST'
);
foreach ($times as $time) {
$dt = DateTime::createFromFormat('Y-m-d H:i:s T', $time, new DateTimeZone('Europe/London'));
echo "Localised:\n";
echo $dt->format($format) . "\n\n";
echo "Putting into UTC:\n";
$dt->setTimezone(new DateTimeZone('UTC'));
echo $dt->format($format) . "\n\n";
}