or download this
$query = "SELECT distinct date, priceInCents FROM META_VAL WHERE date
+>= DATE_SUB(NOW(), INTERVAL 7 DAY) ORDER BY date ASC";
$sth = $dbh->prepare($query);
...
timefmt => '%Y-%m-%d $H:%M:%S', # input time format
);
$mygraph->plot2d($data);