Yesterday, Today, One week for MySQL - PHP

$today=date("Y-m-d");

$m= date("m"); // Month value
$de= date("d"); //today's date
$y= date("Y"); // Year value

$sevenDaysBefore = date('Y-m-d', mktime(0,0,0,$m,($de-7),$y));
$thirtyDaysBefore = date('Y-m-d', mktime(0,0,0,$m,($de-30),$y));