Building a Printable Monthly Planner in PHP

Tutorial Overview

This tutorial demonstrates how to build a dynamic monthly event planner and form generator using PHP. By combining PHP's native DateTimeImmutable object with loops and HTML table structures, you can generate a fully interactive calendar grid where users can input custom events for any day of the month.

Key Features:

• Dynamic month-to-month navigation with automatic year boundary rollovers.
• Weekday alignment offset calculation using date('w').
• Form textareas embedded within daily calendar cells for event entry.

Complete Source Code

You can copy the complete PHP script below and use it on your local server:

<?php
session_start();
$prm = filter_input(INPUT_GET, 'prm', FILTER_VALIDATE_INT);
$chm = filter_input(INPUT_GET, 'chm', FILTER_VALIDATE_INT);
$current_month = $prm ? $prm : (int)date("n");
$current_year = (int)date("Y");

try {
    $date_obj = DateTimeImmutable::createFromFormat('!Y-n-j', "$current_year-$current_month-1");
    if ($chm !== null && $chm !== 0) {
        $date_obj = $date_obj->modify(($chm > 0 ? "+{$chm} month" : "{$chm} month"));
    }
} catch (Exception $e) {
    $date_obj = new DateTimeImmutable('first day of this month');
}

$m = (int)$date_obj->format('n');
$y = (int)$date_obj->format('Y');
$no_of_days = (int)$date_obj->format('t');
$mn = $date_obj->format('M');
$yn = $date_obj->format('Y');
$j = (int)$date_obj->format('w');

$adj = '';
for($k = 1; $k <= $j; $k++){                        
    $adj .="<td>&nbsp;</td>";
}

$body = "<form method='post' action='php_monthly_plannerck.php' name='f1'><input type='hidden' name='prm' value='$m'>";
$body .= "<table border='1' bordercolor='#FFFF00' cellspacing='0' cellpadding='0' align='center' width='90%'><tr><td>";
$body .= "<table cellspacing='0' cellpadding='0' align='center' width='100%' border='1'>
<tr>
<td align='center' bgcolor='#ffff00'><a href='php_monthly_planner.php?prm=$m&chm=-1' rel='nofollow'>&lt;</a></td>
<td colspan='5' align='center' bgcolor='#ffff00'><b>$mn $yn</b></td>
<td align='center' bgcolor='#ffff00'><a href='php_monthly_planner.php?prm=$m&chm=1' rel='nofollow'>&gt;</a></td>
</tr>
<tr>";
$body .= "<td><b>Sun</b></td><td><b>Mon</b></td><td><b>Tue</b></td><td><b>Wed</b></td><td><b>Thu</b></td><td><b>Fri</b></td><td><b>Sat</b></td></tr><tr>";

for($i = 1; $i <= $no_of_days; $i++){
    $body .= $adj . "<td valign='top'>$i<br><textarea name='t[$i]' rows='2' cols='7'></textarea></td>";
    $adj = '';
    $j++;
    if($j == 7){
        $body .= "</tr><tr>"; 
        $j = 0;
    }
}
$body .= "</tr><tr><td colspan='7' align='center'><b>plus2net.com Calendar Generator</b></td></tr>";
$body .= "</table></td></tr></table>";

$body .= "<table border='0' width='50%' cellspacing='0' cellpadding='0' align='center' class='mt-3'><tr>
<td align='center'>Total Width</td><td><input type='text' name='t_width' value='770' size='4'></td>
<td align='center'>Cell Height</td><td><input type='text' name='c_height' value='50' size='4'></td>
</tr>";
$body .= "<tr><td colspan='4' align='center' class='pt-3'>
<input type='submit' value='Display Printer Friendly Page' class='btn btn-primary btn-sm mx-1'/>
<input type='submit' value='Display HTML Code' class='btn btn-secondary btn-sm mx-1'/>
</td></tr></table></form>";

echo $body;