Function that returns time ago results from a strtotime-friendly string such as a datetime

timeago.php

<?php

function timeago( $params )
{
	$conversions = array(
		'millisecond' => 1,
		'second' => 1000,
		'minute' => 60,
		'hour' => 60,
		'day' => 24,
		'month' => 30,
		'year' => 12
	);
	
	# Set up params.
	$threshold = isset($params['threshold']) ? $params['threshold'] : 0;
	$now = strtotime('now');
	$time = strtotime($params['time']);
	$delta = ($now - $time) * 1000;

	if ($delta <= $threshold) {
		return "Just now";
	}
	
	foreach ($conversions as $key => $val) {
		if($delta < $conversions[$key]) {
			break;
		} else {
			$units = $key;
			$delta = $delta / $conversions[$key];
		}
	}
	
	$delta = floor($delta);
	if($delta != 1) { $units .= 's'; }
	return implode(' ', array($delta, $units, 'ago'));
}