Setting values in a config file is a great way to store data in one place, that can be accessed by lots of other pages... and a great way to change things quickly when a site goes live.

However, sometimes you want to store several things that are similar, so an array would be a good idea... This is how it's used in CodeIgniter...

The following is in the config/config.php file:

$config['format_time'] = array(
    0 => 'd/m/Y'        // dd/mm/yyyy
    , 1 => 'd/m/y'      // dd/mm/yy
    , 2 => 'd/m/Y H:i'  // dd/mm/yyyy hh:ss
    , 3 => 'd/m/y H:i'  // dd/mm/yy hh:ss
    , 4 => "jS M 'y"    // 1st Jan '14
    , 5 => 'U'          // Epoch
    , 6 => 'd M Y'      // JS Date Picker Format
    , 7 => 'd M Y H:i'  // JS Time Picker Format
    , 8 => 'jS M Y'     // 1st Jan 2014
);

This is how you use in in your view:

<?php echo date($this->config->item(0,'format_time'), strtotime($itemFromDatabase)); ?>

Where the $itemFromDatabase looks like:2014-03-29 19:00:00