- var_dump: documentation ( source)
- array_replace: documentation ( source)
<?php
$coordinates = array('Years' => 'All Years',
'Months' => 'All Months',
'Days' => 'All Days',
'Hours' => 'All Hours',
'Time' => 'All Time');
$newCoordinates = array('Years' => 2014);
var_dump(array_replace($coordinates, $newCoordinates));