How to convert a unix timestamp to an ISO8601 timestamp in PHP?

Question

I am trying to extract unix timestamp from mysql and convert it to ISO8601 timestamp. I need it in order to format date into facebook-like(or stack-overflow-like:) '30 minutes ago' instead of displaying the exact date and time. Has anyone dealt with it?

Answer 1

$timestamp = '1268932078';

$iso8601 = date('c', $timestamp);

But there are built-in functions to help you with this if you don't want to roll your own, e.g.: DateTime::diff.

Answer 2

Facebook Like Time Format:

A time difference function that outputs the time passed in facebook's style: 1 day ago, or 4 months ago.

http://www.php.net/manual/en/function.time.php#89415

function nicetime($date)
{
    if(empty($date)) {
        return "No date provided";
    }
$periods = array("second","minute","hour","day","week","month","year","decade");
$lengths = array("60","60","24","7","4.35","12","10");   
$now = time();
$unix_date = strtotime($date);
    if(empty($unix_date)) {    
        return "Bad date";
    }
    if($now > $unix_date) {    
        $difference     = $now - $unix_date;
        $tense         = "ago";
        
    } else {
        $difference     = $unix_date - $now;
        $tense         = "from now";
    }    
    for($j = 0; $difference >= $lengths[$j] && $j < count($lengths)-1; $j++) {
        $difference /= $lengths[$j];
    }   
    $difference = round($difference);   
    if($difference != 1) {
        $periods[$j].= "s";
    }   
    return "$difference $periods[$j] {$tense}";
}

// convert timestamp to date ISO8601 
$timestamp = date('c', '1268932078');
// convert to nice date
echo nicetime($timestamp);   //40 years ago