php如何将月份区间转为时间戳

$start_month = 5;
$end_month = 10;
$year = 2023;
 
for ($month=$start_month; $month<=$end_month; $month++) {
  $days_in_month = cal_days_in_month(CAL_GREGORIAN, $month, $year);
  $total_days = $days_in_month * ($month - $start_month);
  $timestamp = strtotime("{$year}-{$month}-1 00:00:00") + $total_days * 86400;
  echo $timestamp . '<br>';
}