CodeIgniter comes with a really useful calendar helper that allows you to display months in a grid. It is possible to develop functionality to pull events from a database (such as a table that stores diary appointments) and indicate to the user if there is an appointment on a given day.
As we're storing appointments in a database, we'll need a database table. Copy the following code into your database:
CREATE TABLE `appointments` ( `app_id` int(11) NOT NULL AUTO_INCREMENT, `app_date` varchar(11) NOT NULL, `app_url` varchar(255) NOT NULL, `app_name` varchar(255) NOT NULL, PRIMARY KEY (`app_id`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=5 ; INSERT INTO `appointments` (`app_id`, `app_date`, `app_url`, `app_name`) VALUES (1, '1375465528', 'http://localhost/1', 'My Appointment'), (2, '1375638327', 'http://localhost/2', 'My Second Appointment'), (3, '1375897527', 'http://localhost/3', 'My Third Appointment...