PHP/mysql:hur visar jag poster sorterade efter tid och grupperade efter datum?

Grov halv-pseudokod:

$records = /* SELECT * FROM `records` ORDER BY `entry_time` */;

$date = null;
foreach ($records as $record) {
    $currentDate = date('Ymd', $record['entry_time']);
    if ($currentDate != $date) {
        printf('<h1>%s</h1>', date('Y-m-d', $record['entry_time']));
    }
    $date = $currentDate;

    echo date('H:i', $record['entry_time']);
}