Match mysql dates in a string.

timestamp.php

<?php

$d = function ($name, $length = '1,2') {
    return sprintf('(?<%s>\d{%s}>)', $name, $length);
};
$matches2time = function ($matches, $format = DateTime::W3C) {
    $year = $month = $day = $time = $hour = $minute = $second = null;
    extract($matches);

    $dt = new DateTime();
    $dt->setDate((int)$year, (int)$month, (int)$day);
    if (isset($time)) {
        if (isset($second)) {
            $dt->setTime((int)$hour, (int)$minute, (int)$second);
        } else {
            $dt->setTime((int)$hour, (int)$minute);
        }
    }
    return is_int($format) ? $dt->format($format) : $dt->getTimestamp();
};
$sep = '[-_\s]+';
$sep2 = "($sep|:)";
$sep3 = "($sep|T)";

$datepat = vsprintf(
    "@(^|$sep)%s$sep%s$sep%s$sep3(?<time>$sep2%s($sep2%s)?)?($sep|$)@i",
    array(
        $d('year', 4),
        $d('month', '1,2'),
        $d('day', '1,2'),
        $d('hour', '1,2'),
        $d('minute', '1,2'),
        $d('second', '1,2')
    )
);