function weekNumber($timestamp = 'today') {
if($timestamp == 'today') $timestamp = time();
return date("W", $timestamp) - date("W", strtotime(date("Y-m-01", $timestamp))) + 1;
}
echo weekNumber();
// echo weekNumber(mktime(0, 0, 0, 5, 18, 2020));
追问如果是当天呢? 怎么调用呢?