php语法如何获取某个日期是星期几/获取当前月份的天数

<?php
  $date = strtotime("2023-08-02");
  $day_of_week = date("l", $date);
  echo "该日期是星期：".$day_of_week;
?>

<?php
  $current_month = date("m");
  $days_in_month = cal_days_in_month(CAL_GREGORIAN, $current_month, date("Y"));
  echo "当前月份的天数：".$days_in_month;
?>