Hongtting

<?
 
$YY = '2019';
$MM = '01';
 
$firstday = mktime(0,0,0, date($MM), 1, date($YY)); //이번달 1일
$prev_month = strtotime("-1 month", $firstday); //한달전
 
echo "$prev_month <br>";
 
$lastday = date("Y-m-d H:i:s", $prev_month);
 
echo "$lastday";
 
?>