Style switchers have become a popular feature on websites these days. CSS style sheets allow a Web Designer to change the look and feel of a website with little effort. Some sites use “Day” and “Night” type of style switchers that automatically change the site theme based on the time of day.

This tutorial shows you how to create a time based CSS style sheet switcher using PHP that lets you change multiple style sheets at once at specific times of the day. There’s also a little bit of jQuery UI thrown in just for fun!

Why PHP instead of JavaScript?

The one drawback to using PHP for a time based CSS style sheet switcher is that the time is based on either the web hosting server or on a “time zone” set in the script.

When I was building my personal portfolio site, I created a time based style sheet switcher using JavaScript and jQuery. The time function of the script worked correctly. However, there was always a brief “flash” of the default style sheet when the web pages loaded.

JavaScript heavy websites can have problems with conflicts between various JavaScript scripts. I decided to use PHP instead for the CSS style sheet switcher. Because PHP is server side, there were no JavaScript conflicts and the script worked as expected.

The one drawback to using PHP for a time based CSS style sheet switcher is that the time is based on either the web hosting server or on a “time zone” set in the script. With JavaScript you can set time functions to be based on a user’s computer.

Before We Begin

If you are new to PHP, you need to set up and configure a server environment on your local computer (PHP files can not be viewed in a web browser). My personal preference is XAMPP. This article includes a few software options and basic instructions on how to set up a local server.

Although you can use Notepad to create and edit PHP files, a code editor can be very helpful when writing web pages in PHP and other programming languages. Please refer to these articles for additional information on choosing a code editor:

• 22 Neat Code Editors for Windows
• 10 Versatile Text Editors for OS X

The code used in the tutorial creates a basic CSS style sheet switcher and you can view the demo here. The source files include two additional demos.

Now, let’s get started!

Step 1: Create the 1st CSS Style Sheet (Night)

Create a CSS style sheet called style-1.cssand include the following code:

/*  Default Styles
--------------------------------------------------- */

body {
	margin: 0px;
	padding: 0px;
	background: url("../images/bokeh_2.jpg");
	background-position: top left;
	background-repeat: no-repeat;
	background-attachment: fixed;
	background-color: #666;
	font-size: 20px;
	font-family: Arial, Helvetica, sans-serif;
	color: #fff;
	text-align: left;
}

#wrapper	{
	width: 965px;
	margin: 0 auto;
	position: relative;
}

a:link, a:visited, a:active {
	color: #99ccff;
}

a:hover {
	color: #0073ea;
}

.content_container_1	{
	float: left;
	width: 650px;
	margin: 0px 0px 60px 0px;
}

p.main_description	{
	margin: 5px 0px 50px 0px;
	text-align: center;
}

/* Main Image
--------------------------------------------------- */

.main_image	{
	background: url("../images/main_image_1.jpg");
	background-repeat: no-repeat;
	width: 630px;
	height: 425px;
	border: #fff solid 10px;
	margin: 40px 0px 10px 0px;
}

/*  Tabs
--------------------------------------------------- */

#tabs p	{
	font-family: Arial, Helvetica, sans-serif;
	font-size: 20px;
}

a.tabs_link_1:link, a.tabs_link_1:visited, a.tabs_link_1:active {
	text-decoration: underline;
	color: #0073ea;
	font-weight: bold;
}

a.tabs_link_1:hover {
	text-decoration: underline;
	color: #ff0084;
	font-weight: bold;
}

#tabs .tabs_img	{
	float: left;
	background-color: #ddd;
	padding: 8px;
	margin: 0px 12px 0px 0px;
}

Step 2: Create the 2nd CSS Style Sheet (Morning)

Open style-1.css and save it as style-2.css. Change the body background image from bokeh_2.jpg to bokeh_4.jpg. Change main_image_1.jpg to main_image_4.jpg.

Step 3: Create the 3rd CSS Style Sheet (Afternoon)

Use style-1.css or style-2.css to create a 3rd style sheet style-3.css. Change the body background image to bokeh_3.jpg and the main image to main_image_5.jpg

Step 4: Create the 4th CSS Style Sheet (Evening)

Create a 4th style sheet style-4.css. Change the body background image to bokeh_1.jpg and the main image to main_image_8.jpg

For steps 2 through 4, feel free to change other elements like font colors and image borders. Instead of using the images provided in the source files, you can use your own images to create custom CSS styles.

Step 5: Download jQuery and jQuery UI

To show how the PHP script changes multiple style sheets at once, jQuery Themeroller Themes are being used to style the tabbed content area of the web page.

Go to the jQuery UI Download Page and download the “Flick” and “Start” themes.

Next, go to the official jQuery website and download jQuery.

Step 6: The Markup

Create a PHP file that includes the following code:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>

<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />

<!-- CSS style sheets -->
<?php include("style sheets.php"); ?>

<!-- jQuery / JavaScript -->
<script type="text/javascript" src="js/jquery-1.6.3.min.js"></script>
<script type="text/javascript" src="js/jquery-ui-1.8.16.custom.min.js">></script>
<script type="text/javascript">
	$(function() {
		$( "#tabs" ).tabs();
	});
</script>

<meta name="description" content="This demo uses PHP to change multiple CSS style sheets (Main CSS and jQuery UI Theme) at specific times during a 24 hour period. The timezone for this demo is set to Australia/Melbourne." />
<meta name="keywords" content="time,based,css,stylesheet,switcher,php" />
<title>Simple Time Based CSS Style Sheet Switcher</title>

</head>
<body>

<!-- Begin Wrapper -->
<div id="wrapper">

<!-- Begin Content Container 1 -->
<div class="content_container_1">

<!-- Main Image Switches at Set Times -->
<div class="main_image"></div>
<p class="main_description">
Main Image changes at the times set in PHP Script (Australia/Melbourne).
</p>

<!-- Begin Tabs Area -->
 <div id="tabs">
	<ul>
		<li><a href="#tabs-1">About Envato</a></li>
		<li><a href="#tabs-2">Marketplaces</a></li>
		<li><a href="#tabs-3">Tuts+ Network</a></li>
	</ul>

	<div id="tabs-1">
	<p>
	<img class="tabs_img" src="images/envato_1.jpg" width="300" height="195" alt="About Envato" />
	Envato is a startup based out of Australia with people around the world and sites serving pages every second. We started in a living room in 2006 and have been steadily working to build our company into a world-class contender. Our background is creative, we love open source, we believe that work is about way more than just making money, and we're totally committed to making products that are awesome!
	</p>
	<p>
	<a class="tabs_link_1" href="http://envato.com/" target="_blank" title="Visit The Envato Website">Visit The Envato Website</a>
	</p>
	</div>

	<div id="tabs-2">
	<p>
	<img class="tabs_img" src="images/marketplace_1.jpg" width="300" height="195" alt="Marketplaces" />
	The Envato Marketplaces allow anyone to buy or sell digital goods like WordPress themes, background music, After Effects project files, Flash templates and much more. The marketplaces are home to a thriving community of over 500,000 users, authors and buyers and every day hundreds of new files are added.
	</p>
	<p>
	<a class="tabs_link_1" href="http://themeforest.net/" target="_blank" title="Visit the Theme Marketplace">Visit the Theme Marketplace</a>
	</p>
	</div>

	<div id="tabs-3">
	<p>
	<img class="tabs_img" src="images/psdtuts_1.jpg" width="300" height="195" alt="Tuts+ Network" />
	At Envato we're very passionate about education, that's why we've created one of the most popular networks of educational blogs around. Tuts+ serves up over 18 million pageviews a month across its many subsites on subjects like graphics, web development, audio production, iPhone development and motion graphics.
	</p>
	<p>
	<a class="tabs_link_1" href="http://tutsplus.com/" target="_blank" title="Visit Tuts+ Hub">Visit Tuts+ Hub</a>
	</p>
	</div>

</div>
<!-- End Tabs Area -->

</div>
<!-- End Content Container 1 -->

</div>
<!-- End Wrapper -->

</body>
</html>

Step 7: PHP CSS Stylesheet Switcher Code

Create a PHP file that includes the following code:

<?php

date_default_timezone_set("Australia/Melbourne"); // Set default time zone

$time = date("H"); // Set the time in 24 hour format

if (00 <= $time && $time < 07) // 12:00am to 7:00am   Night
	{
	echo
'<link href="css/style-1.css" rel="stylesheet" type="text/css" media="screen" /><link href="css/flick/jquery-ui-1.8.16.custom.css" rel="stylesheet" type="text/css" media="screen" />';
	}

elseif (07 <= $time && $time < 12) // 7:00am to 12:00pm   Morning
	{
	echo
'<link href="css/style-2.css" rel="stylesheet" type="text/css" media="screen" /><link href="css/start/jquery-ui-1.8.16.custom.css" rel="stylesheet" type="text/css" media="screen" />';
	}

elseif (12 <= $time && $time < 18) // 12:00pm to 6:00pm   Afternoon
	{
	echo
'<link href="css/style-3.css" rel="stylesheet" type="text/css" media="screen" /><link href="css/start/jquery-ui-1.8.16.custom.css" rel="stylesheet" type="text/css" media="screen" />';
	}

else // all other hours   Evening
	{
	echo
'<link href="css/style-4.css" rel="stylesheet" type="text/css" media="screen" /><link href="css/flick/jquery-ui-1.8.16.custom.css" rel="stylesheet" type="text/css" media="screen" />';
	}

?>

Breakdown of the Markup

PHP Include for rel="stylesheet" Links

The script for the CSS Style sheet Switcher is going to be contained in a PHP include file called stylesheets.php.

A PHP include() statement includes and evaluates a specified file. The stylesheets.php include file is referenced by this code:

<!-- CSS style sheets -->
<?php include("style sheets.php"); ?>

Because we are using a PHP script to change CSS style sheets at set times, the rel=”stylesheet” links will be generated by the PHP script.

Reference jQuery and jQuery UI Libraries

We need to make sure that the web page references the jQuery and jQuery UI libraries.

Between the head tags of the web page the following code has been added:

<!-- jQuery / JavaScript -->
<script type="text/javascript" src="js/jquery-1.6.3.min.js"></script>
<script type="text/javascript" src="js/jquery-ui-1.8.16.custom.min.js"></script>

Initialize jQuery UI Tabs

This tutorial includes jQuery UI Tabs using the default functionality. The following code initializes the tabs:

<script type="text/javascript">
	$(function() {
		$( "#tabs" ).tabs();
	});
</script>

Container Div for jQuery UI Tabs

<!-- Begin Wrapper -->
<div id="wrapper">

<!-- Begin Content Container 1 -->
<div class="content_container_1">

(Ending </div> tags for Wrapper and Content Container 1 are shown in the Code block for the Markup of the jQuery UI Tabs)

Most of the jQuery UI Widgets are programmed to expand to 100% width of the content area where they are placed.

The container div content_container_1 has been set to a fixed width of 650px in the CSS so that the tabbed content area does not expand the entire width of the screen.

Main Image Markup

In order for the main image to also be changed at set times using the PHP script, it needed to be included on the web page as a CSS background image.

So instead of adding the image to the web page using markup like this:

<img src="main_image_1.jpg" width="630" height="425" alt="Image" />

It was added to the web page as a CSS background image of a <div> with the class “main_image”, like this:

<!-- Main Image Switches at Set Times -->
<div class="main_image"></div>
<p class="main_description">
Main Image changes at the times indicated.
</p>

Markup for the jQuery UI Tabs

The below markup adds the tabbed content area that is powered by jQuery UI and has been styled using jQuery Themeroller Themes.

<!-- Begin Tabs Area -->
 <div id="tabs">
	<ul>
		<li><a href="#tabs-1">About Envato</a></li>
		<li><a href="#tabs-2">Marketplaces</a></li>
		<li><a href="#tabs-3">Tuts+ Network</a></li>
	</ul>

	<div id="tabs-1">
	<p>
	<img class="tabs_img" src="images/envato_1.jpg" width="300" height="195" alt="About Envato" />
	Envato is a startup based out of Australia with people around the world and sites serving pages every second. We started in a living room in 2006 and have been steadily working to build our company into a world-class contender. Our background is creative, we love open source, we believe that work is about way more than just making money, and we're totally committed to making products that are awesome!
	</p>
	<p>
	<a class="tabs_link_1" href="http://envato.com/" target="_blank" title="Visit The Envato Website">Visit The Envato Website</a>
	</p>
	</div>

	<div id="tabs-2">
	<p>
	<img class="tabs_img" src="images/marketplace_1.jpg" width="300" height="195" alt="Marketplaces" />
	The Envato Marketplaces allow anyone to buy or sell digital goods like WordPress themes, background music, After Effects project files, Flash templates and much more. The marketplaces are home to a thriving community of over 500,000 users, authors and buyers and every day hundreds of new files are added.
	</p>
	<p>
	<a class="tabs_link_1" href="http://themeforest.net/" target="_blank" title="Visit the Theme Marketplace">Visit the Theme Marketplace</a>
	</p>
	</div>

	<div id="tabs-3">
	<p>
	<img class="tabs_img" src="images/psdtuts_1.jpg" width="300" height="195" alt="Tuts+ Network" />
	At Envato we're very passionate about education, that's why we've created one of the most popular networks of educational blogs around. Tuts+ serves up over 18 million pageviews a month across its many subsites on subjects like graphics, web development, audio production, iPhone development and motion graphics.
	</p>
	<p>
	<a class="tabs_link_1" href="http://tutsplus.com/" target="_blank" title="Visit Tuts+ Hub">Visit Tuts+ Hub</a>
	</p>
	</div>

</div>
<!-- End Tabs Area -->

</div>
<!-- End Content Container 1 -->

</div>
<!-- End Wrapper -->

The Menu “Tabs” are generated by an unordered list. The content sections are generated by <div> tags that have unique IDs that correspond to anchor links in the <li></li> tags.

For example: <div id=”tabs-1″> corresponds with <a href=”#tabs-1″>

Breakdown of PHP Stylesheet Switcher Code

Set the Default Time Zone:

date_default_timezone_set("Australia/Melbourne"); // Set default time zone

The code date_default_timezone_set sets the default timezone used by all date/time functions in a script.

If the script does not include date_default_timezone_set, then the web hosting server time will be used for all date/time functions in the script.

Please refer to the List of Supported Timezones to find the appropriate timezone for your location.

Newer versions of PHP incorporate “Daylight Savings Times” into the functionality of date_default_timezone_set. Some older versions of PHP do not take “Daylight Savings Times” into account.

Set the Time in 24 Hour Format:

$time = date("H"); // Set the hour in 24 hour format

date(“H”) formats the local time/date in a 24-hour format of an hour, with leading zeros. Click Here to view information about the 24-hour clock.

Breakdown of If, Elseif, Else Statement

I’ve broken down the rest of the PHP code to show how the PHP script will function line by line. There are several functions being utilized in the code including:

• If, Elseif, Else Statement.
• Echo
• Comparison Operators
• Logical Operators

if

if (00 <= $time && $time < 07) // 12:00am to 7:00am   Night
	{
	echo
'<link href="css/style-1.css" rel="stylesheet" type="text/css" media="screen" /><link href="css/flick/jquery-ui-1.8.16.custom.css" rel="stylesheet" type="text/css" media="screen" />';
	}

If 00 (midnight) is Less than or equal to current time AND current time is Less than 07 (7:00am) Then the script will apply style-1.css and flick CSS style sheets.

elseif

elseif (07 <= $time && $time < 12) // 7:00am to 12:00pm   Morning
	{
	echo
'<link href="css/style-2.css" rel="stylesheet" type="text/css" media="screen" /><link href="css/start/jquery-ui-1.8.16.custom.css" rel="stylesheet" type="text/css" media="screen" />';
	}

If 07 (7:00am) is Less than or equal to current time AND current time is Less than 12 (12:00pm) Then the script will apply style-2.css and start CSS style sheets.

elseif

elseif (12 <= $time && $time < 18) // 12:00pm to 6:00pm   Afternoon
	{
	echo
'<link href="css/style-3.css" rel="stylesheet" type="text/css" media="screen" /><link href="css/start/jquery-ui-1.8.16.custom.css" rel="stylesheet" type="text/css" media="screen" />';
	}

If 12 (12:00pm) is Less than or equal to current time AND current time is Less than 18 (6:00pm) Then the script will apply style-3.css and start CSS style sheets.

else

else // all other hours   Evening
	{
	echo
'<link href="css/style-4.css" rel="stylesheet" type="text/css" media="screen" /><link href="css/flick/jquery-ui-1.8.16.custom.css" rel="stylesheet" type="text/css" media="screen" />';
	}

If NONE of the conditions are met in the “if…elseif” statements, Then the script will apply style-4.css and flick CSS style sheets.

Conclusion

With CSS, you can create many different styles for your web pages. Using PHP, you can apply those styles dynamically to your website. Throw in a little jQuery UI, and your web pages will not only be fun for you to create, but fun for your visitors as well!

If you have any questions about this tutorial, please ask them below, Thank you so much for reading!