PHP calendars can be very useful. You can do things as simple as showing the date, and as complex as an online booking system. In this tutorial we will show you how to generate a very simple PHP calendar.

Introduction

March 2010
Sun    Mon    Tue    Wed    Thu    Fri    Sat

     1    2    3    4    5    6

7    8    9    10    11    12    13

14    15    16    17    18    19    20

21    22    23    24    25    26    27

28    29    30    31     



Here's a very simple, but very complete, PHP script to print out a calendar. It does one thing, but does it well (which is how it should be). Neat bonus features include the ability to link certain days in the calendar to a web page - useful for a weblog. You can also assign stylesheet classes to specific days, and provide content for an individual day.


To use this code, just save the script to your server, include() it in your code, and display the output of generate_calendar().


New features: Version 2.1 is now locale-aware. All day and month names are automatically generated specific to your locale. Version 2.2 allows you to choose what day your weeks start on. See examples in the examples section.


Functions


Just one:


function generate_calendar($year, $month, $days = array(), $day_name_length = 3, $month_href = NULL, $first_day = 0, $pn = array())

generate_calendar returns a string containing the output HTML. $year and $month are obvious. However, a neat side effect of using PHP's mktime function internally is that generate_calendar does "date rounding". So, basically, if you try to do month 13 of 2002, it'll round to January of 2003. See the documentation for mktime.

$days is an optional array that can contain information you want to specify for each day, including a location to link that day to, a stylesheet class for that day, and any content you want to appear for that day of the calendar. For example, an array passed for the days parameter might look something like this:

<?php

$days = array(

    2=>array('/weblog/archive/2004/Jan/02','linked-day'),

    3=>array('/weblog/archive/2004/Jan/03','linked-day'),

    8=>array('/weblog/archive/2004/Jan/08','linked-day'),

    22=>array('/weblog/archive/2004/Jan/22','linked-day'),

);

?>

Each key corresponds to the day of the month, and each value is an array containing one to three elements. The first element is the location you want the day to link to, the second element is a space-separated list of classes (for stylesheets), and the third element is content that you want to appear in that day's cell, instead of just the day's number.


$day_name_length (optional, defaults to 3) is the number of characters to show for the day name ("Monday", "Tuesday", etc.). If you choose zero, the day headings don't display at all, and if you choose >3 it displays the whole name of the day.

$month_href is the location you'd like the month to be a link to (optional).

$first day is the number of the day you want your weeks to start on. Sunday is 0, Monday is 1, etc. Defaults to 0, hence Sunday.

$pn contains the links for the previous and next months to link to (hence, 'pn'). It should be in the following format: $pn = array('&lt;'=>'prev-link','&gt;'=>'next-link'); Note that it's not necessary that the key for next and previous be < (&lt) and > (&gt;). They could also be things like ← (&larr;) and → (&rarr;) or « (&laquo;) and » (&raquo;). In addition, it's important that you define them in the order just shown (previous before next in the array). If you just want to have a previous link, just define the first. If you just want to have a next link, you must define the first with a NULL key and then define the second. If one of the "directions" is defined but the link field is blank, the key (such as < or >) will still be shown, but it won't be a link.

Examples
Show the current month
 
       

March 2010
Sun    Mon    Tue    Wed    Thu    Fri    Sat

     1    2    3    4    5    6

7    8    9    10    11    12    13

14    15    16    17    18    19    20

21    22    23    24    25    26    27

28    29    30    31     

     
           
Code

<?php
    $time = time();

    echo generate_calendar(date('Y', $time), date('n', $time));
?>
 



All color and style information is configurable with stylesheets.
Specify the number of characters to show for day name

      

March 2010
Su    Mo    Tu    We    Th    Fr    Sa

     1    2    3    4    5    6

7    8    9    10    11    12    13

14    15    16    17    18    19    20

21    22    23    24    25    26    27

28    29    30    31     

     
           
Code

<?php

    $time = time();

    echo generate_calendar(date('Y', $time), date('n', $time), NULL, 2);

?>     
   



As you can see, it only shows the first two letters of each day heading.