Colspan breaks table - php

Question

ORIGINAL
I have a page that displays all the company boardrooms and bookings for a certain day. It looks like this:
As you can see, some of the rows create an extra <td>
Here is the code that generates the table:
<table celladding="0" cellspacing="0" class="table table-bordered col-xs-12">
<thead>
<tr style="background-color:#FFF">
<?php
$width = (100 / (count($boardrooms->toArray()) + 1));
$width = 100 / 7;
?>
<th style="border-right:none; width:<?= $width; ?>%; border-bottom: none;">Boardroom</th>
<?php
foreach($boardrooms as $boardroom) { ?>
<th rowspan="2" style="width:<?= $width; ?>%"><?php echo $boardroom ?></th>
<?php } ?>
</tr>
<tr>
<th>Time</th>
</tr>
</thead>
<?php
$writerow = false;
for($hour = 8; $hour < 17; $hour++) {
for($minute = 0; $minute < 4; $minute++) {
echo '<tr><td>' . $hour . ':' . str_pad(($minute*15),2,"0") . '</td>';
foreach($boardrooms as $boardroom) {
foreach($boardroomBookings as $booking) {
if(date('H:i',strtotime($hour . ':' . str_pad(($minute*15),2,"0"))) >= date('H:i',strtotime($booking->start_time)) &&
date('H:i',strtotime($hour . ':' . str_pad(($minute*15),2,"0"))) < date('H:i',strtotime($booking->end_time)) &&
$boardroom == $booking->boardroom->name && (empty($boardroomWritten[$booking->id]) || !$boardroomWritten[$booking->id])) {
$boardroomWritten[$booking->id] = true;
$writerow = true;
$rowspan = (strtotime($booking->end_time) - strtotime($booking->start_time))/900;
echo '<td style="background-color:#8cc63f; border-bottom:none" rowspan="' . $rowspan . '">' . $this->Html->link($booking->name, array('action' => 'view', $booking->id)) . '</td>';
break;
} else {
$writerow = false;
}
}
if(!$writerow) {
echo '<td></td>';
}
}
echo '</tr>';
}
}
?>
</table>
How can I prevent the rows from displaying the extra empty cell on rows that have a booking?
EDIT
Here's the same table with black borders:
And what it looks like without a booking:
And what it should look like with a booking:

Answer 1

If you don't have a booking you need to insert a td pair unless you are inside a colspan:
<?php
for($hour = 8; $hour < 17; $hour++) {
for($minute = 0; $minute < 4; $minute++) {
$bookTime = date('H:i ',strtotime($hour . ':' . str_pad(($minute*15),2,"0"))) ;
echo '<tr><td>' . $bookTime . '</td>';
foreach($boardrooms as $boardroom) {
$hasBooking = false;
foreach($boardroomBookings as $booking) {
$sTime = strtotime($booking->start_time) ;
$eTime = strtotime($booking->end_time) ;
$startTime = date('H:i',$sTime);
$endTime = date('H:i', $eTime) ;
if($bookTime >= $startTime && $bookTime < $endTime && $boardroom == $booking->boardroom->name) {
$hasBooking = true;
if(empty($boardroomWritten[$booking->id]) || !$boardroomWritten[$booking->id]) {
$boardroomWritten[$booking->id] = true;
$rowspan = ($eTime - $sTime)/900 ;
echo '<td style="background-color:#8cc63f; border:1px black solid" rowspan="' . $rowspan . '">' . "somelink" . '</td>';
break;
}
}
}
if (!$hasBooking) {
echo "<td></td>" ;
}
}
echo '</tr>';
}
}