<?php

echo 'event happened ' . humanTiming('2014-04-20 17:25:43') . ' ago';

function humanTiming ($time)
{
    $time = strtotime($time);
    $time = time() - $time;

    $tokens = array (
        31536000 => 'year',
        2592000 => 'month',
        604800 => 'week',
        86400 => 'day'
    );

    foreach ($tokens as $unit => $text) {
        if ($time < $unit) continue;
        $numberOfUnits = floor($time / $unit);
        return $numberOfUnits.' '.$text.(($numberOfUnits>1)?'s':'');
    }
}

?>