$rawTime = substr($tagParts[1], 0, 1)-$_GET['tz-offset'];
$time24 = str_replace('.5',':30', $rawTime);
$time12 = $time24-12;

if ($time12 < 0) {
    $time = $b+12;
    tm = "am";
} else if ($time12 == 0) {
    $time = $b+12;
    $tm = "pm";
} else {
    $tm = "pm";
}
$localTime = $time.$tm;