ช่วยแนะนำวิธีเขียนโค๊ด ในการตรวจสอบข้อมูลย้อนหลัง ได้ ไม่เกินระยะ เวลาที่กำหนดครับ

$start_date = date("d/m/Y",strtotime("-90 day"));
echo $start_date;

<?
$start_date = date("d/m/Y",strtotime("-90 day")); 
//echo $start_date;

$array_date = explode('/',$start_date);
$start_day = $array_date[0];
$start_month = $array_date[1];
$start_year = $array_date[2];
$last_day_of_month = date("d", mktime(0, 0, 0, $start_month+1, 0, $start_year));


$end_date=date("d");
$end_month=date("m");
$end_year=date("Y");


echo "From : ";
echo "<select name=\"Sdate\">";
for($start_day;$start_day<=$last_day_of_month;$start_day++){
	echo "<option value=\"$start_day\">$start_day</option>";
}
echo "</select>-";

echo "&nbsp;";

echo "<select name=\"Smonth\">";
for($start_month;$start_month<=12;$start_month++){
	echo "<option value=\"$start_month\">$start_month</option>";
}
echo "</select>-";

echo "&nbsp;";

echo "<select name=\Syear\">";
for($start_year;$start_year<=date(Y);$start_year++){
	echo "<option value=\"$start_year\">$start_year</option>";
}
echo "</select>";




echo " To ";
echo "<select name=\"Edate\">";
for($day=1;$day<=$end_date;$day++){
	echo "<option value=\"$day\">$day</option>";
}
echo "</select>-";

echo "&nbsp;";

echo "<select name=\"Emonth\">";
for($month=1;$month<=$end_month;$month++){
	echo "<option value=\"$month\">$month</option>";
}
echo "</select>-";

echo "&nbsp;";

echo "<select name=\Eyear\">";
for($year=2010;$year<=date(Y);$year++){
	if($year==$end_year){
		echo "<option value=\"$year\" selected>$year</option>";	
	}else{
		echo "<option value=\"$year\">$year</option>";
	}
}
echo "</select>";
?>