$re = '/\d{4}(-)\d{2}(-)\d{4}(:)\d{2}(:)\d{2}/';
$str = '"asd:sdfsdgf-abc2016-08-2212:05:00xyzabc2015-08-2212:05:00xyzabc2014-08-2212:05:00xy-sdf:z";
';
$subst = "";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
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