<---ใส่สีใน table ครับ ง่ายๆ มาช่วยหน่อย ใส่สีตามวันเสาร์อาทิตย์--->

function date_in_period($format, $start, $end, $skip = NULL){
	$output = array();
	$days = floor((strtotime($end) - strtotime($start))/86400);
	for($i=0;$i<=$days;$i++){
		$in_period = strtotime("+" . $i . " day", strtotime($start));
		if(is_array($skip) and in_array(date("D",$in_period), $skip)){
			continue;
		}
		array_push($output, date($format, $in_period));
	}
	return $output;
}

$date_color = date_in_period("d", "$start", "$end", array("Mon", "Tue", "Wed", "Thu", "Fri"));

<table>
<tr>
for($day=1;$day<=$numday;$day++)
{
foreach($date_color as $day_color)
				{
					if($day == $day_color)
						{
							$bgcolor = red;
							//echo $day_color." ";
						}
				}
 <td style="background-color:<?=$bgcolor;?>;">...ข้อมูล...</td>
}
</tr>
</table>