Array to Calendar-Table - php

Question

I created the following Array ($stuArr) in PHP.
I want to print the Array in an HTML-Table so that I can create a Table like this (Calendar-System):
The numbers in the table are the dates of the month.
And each user has a own row. I generate the table with this:
$days = cal_days_in_month(CAL_GREGORIAN, $month, $year);
$days = $days + 2;
echo "<table border='1'>";
echo "<tr>";
for ($j = 0; $j < $days; $j++) {
echo "<th>$j</th>";
}
echo "</tr>";
//Person
$file = file_get_contents('MOCK_DATA-100.json');
$data = json_decode($file);
//Events
$file2 = file_get_contents('calendar.json');
$data2 = json_decode($file2);
$stuArr = [];
foreach($data as $student) {
$id = $student->id;
$name = $student->name;
$mark = false;
foreach($data2 as $cal) {
if($cal->resource == $id) {
$start = new DateTime(substr($cal->start, 0, 10));
$end = new DateTime(substr($cal->end, 0, 10));
$interval = DateInterval::createFromDateString('1 day');
$period = new DatePeriod($start, $interval, $end);
$dd = [];
if($month == $start->format('n')) {
foreach ($period as $dt) {
if($month != $dt->format('n'))
break;
$dd[] = $dt->format("j");
}
$stuArr[] = [$id, $dd];
}
}
}
}
var_export($stuArr);
foreach($stuArr as $student) {
$id = $student[0];
$dates = $student[1];
}
echo "</table>";
Output of var_export($stuArr);:
array ( 0 => array ( 0 => '2', 1 => array ( 0 => '22', 1 => '23', 2 => '24', 3 => '25', ), ), 1 => array ( 0 => '3', 1 => array ( 0 => '23', 1 => '24', 2 => '25', ), ), )
Thanks for your help! Regards, Fynn
If you have any question for me or need an explanation of some part of the code, just say it!!!
Error:

Answer 1

Try the below code. I can see you printed o-29 as days, try starting from 1 instead of 0 in the loop.
// update inside the Student loop, previous code remains as it is
foreach($stuArr as $student) {
$dates = $student[1];
echo "<tr>";
for ($j = 1; $j <= $days; $j++) {
if(in_array($j, $dates))
echo "<td>X</t>";
else
echo "<td> </td>";
}
echo "</tr>";
}