Time calculation has some questions. List the most recent 6 months before and after

Time calculation problem Ah ... List the most recent 6 months before and after

$arr = Array ();
$nowd = Date ("Ym");
$arr [] = Date ("Ym", Strtotime ("-6 month"));
$arr [] = Date ("Ym", Strtotime ("-5 month"));
$arr [] = Date ("Ym", Strtotime ("-4 Month"));
$arr [] = Date ("Ym", Strtotime ("-3 month"));
$arr [] = Date ("Ym", Strtotime ("-2 Month"));
$arr [] = Date ("Ym", Strtotime ("-1 month"));

$arr [] = Date ("Ym");

$arr [] = Date ("Ym", Strtotime ("+1 Month"));
$arr [] = Date ("Ym", Strtotime ("+2 Month"));
$arr [] = Date ("Ym", Strtotime ("+3 Month"));
$arr [] = Date ("Ym", Strtotime ("+4 Month"));
$arr [] = Date ("Ym", Strtotime ("+5 Month"));
$arr [] = Date ("Ym", Strtotime ("+6 Month"));

for ($i =0; $i <>
echo "". $arr [$i]. ",";
if ($i%3==0)
Echo '
';
}


?>

Print it out in the middle with 2 x 201203

201204 missing ...

Only today 2012 03 31 The whole day when the usual is normal, seeking analysis ...

Please set the date to No. 3.31 if you are testing.

------Solution--------------------
or use your code.

$nowd = Date ("Y-m-1");
The shape is like
$arr [] = Date ("Ym", Strtotime ("-6 month"));
are changed to form as
$arr [] = Date ("Ym", Strtotime ("-6 month $nowd"));
You can do it.

