<?php
    function test_parse_time($f)
    {
        if (preg_match("/[0-9]{12}/", $f)) {
            $type = "YYYYMMDDHHii";
        } else if (preg_match("/[0-9]{8}\ [0-9]{4}/", $f)) {
            $type = "YYYYMMDD HHii";
        } else if (preg_match("/[0-9]{4}-[0-9]{2}-[0-9]{2}/", $f)) {
            $type = "YYYY-MM-DD";
        } else {
            $type = "*unknown*";
        }

        echo "This is a $type format.\n";
    }
?>

<?php
   
    include 'parse_time.php';

    $formats = array('2004-08-17 21:20', '20040817 2120');
    foreach ($formats as $format) {
        test_parse_time($format);
    }
?>