function time_elapsed_string($ptime)
{
    $etime = time() - $ptime;

    if ($etime < 1)
    {
        return '0 seconds';
    }

    $a = array( 365 * 24 * 60 * 60  =>  'year',
                 30 * 24 * 60 * 60  =>  'month',
                      24 * 60 * 60  =>  'day',
                           60 * 60  =>  'hour',
                                60  =>  'minute',
                                 1  =>  'second'
                );
    $a_plural = array( 'year'   => 'years',
                       'month'  => 'months',
                       'day'    => 'days',
                       'hour'   => 'hours',
                       'minute' => 'minutes',
                       'second' => 'seconds'
                );

    foreach ($a as $secs => $str)
    {
        $d = $etime / $secs;
        if ($d >= 1)
        {
            $r = round($d);
            return $r . ' ' . ($r > 1 ? $a_plural[$str] : $str) . ' ago';
        }
    }
}

这其实是我找到的一个更好的解决方案。使用jQuery，但它的工作完美。此外，它会自动刷新类似于SO和Facebook的方式，所以你不需要刷新页面就能看到更新。

这个插件将读取<time>标签中的datetime attr，并为您填写它。

e.g. "4 minutes ago" or "about 1 day ago

http://timeago.yarp.com/

$time_elapsed = timeAgo($time_ago); //The argument $time_ago is in timestamp (Y-m-d H:i:s)format.

//Function definition

function timeAgo($time_ago)
{
    $time_ago = strtotime($time_ago);
    $cur_time   = time();
    $time_elapsed   = $cur_time - $time_ago;
    $seconds    = $time_elapsed ;
    $minutes    = round($time_elapsed / 60 );
    $hours      = round($time_elapsed / 3600);
    $days       = round($time_elapsed / 86400 );
    $weeks      = round($time_elapsed / 604800);
    $months     = round($time_elapsed / 2600640 );
    $years      = round($time_elapsed / 31207680 );
    // Seconds
    if($seconds <= 60){
        return "just now";
    }
    //Minutes
    else if($minutes <=60){
        if($minutes==1){
            return "one minute ago";
        }
        else{
            return "$minutes minutes ago";
        }
    }
    //Hours
    else if($hours <=24){
        if($hours==1){
            return "an hour ago";
        }else{
            return "$hours hrs ago";
        }
    }
    //Days
    else if($days <= 7){
        if($days==1){
            return "yesterday";
        }else{
            return "$days days ago";
        }
    }
    //Weeks
    else if($weeks <= 4.3){
        if($weeks==1){
            return "a week ago";
        }else{
            return "$weeks weeks ago";
        }
    }
    //Months
    else if($months <=12){
        if($months==1){
            return "a month ago";
        }else{
            return "$months months ago";
        }
    }
    //Years
    else{
        if($years==1){
            return "one year ago";
        }else{
            return "$years years ago";
        }
    }
}

# This function prints the difference between two php datetime objects
# in a more human readable form
# inputs should be like strtotime($date)
function humanizeDateDiffference($now,$otherDate=null,$offset=null){
    if($otherDate != null){
        $offset = $now - $otherDate;
    }
    if($offset != null){
        $deltaS = $offset%60;
        $offset /= 60;
        $deltaM = $offset%60;
        $offset /= 60;
        $deltaH = $offset%24;
        $offset /= 24;
        $deltaD = ($offset > 1)?ceil($offset):$offset;      
    } else{
        throw new Exception("Must supply otherdate or offset (from now)");
    }
    if($deltaD > 1){
        if($deltaD > 365){
            $years = ceil($deltaD/365);
            if($years ==1){
                return "last year"; 
            } else{
                return "<br>$years years ago";
            }   
        }
        if($deltaD > 6){
            return date('d-M',strtotime("$deltaD days ago"));
        }       
        return "$deltaD days ago";
    }
    if($deltaD == 1){
        return "Yesterday";
    }
    if($deltaH == 1){
        return "last hour";
    }
    if($deltaM == 1){
        return "last minute";
    }
    if($deltaH > 0){
        return $deltaH." hours ago";
    }
    if($deltaM > 0){
        return $deltaM." minutes ago";
    }
    else{
        return "few seconds ago";
    }
}

此函数不是为英语语言而设计的。我把这些单词翻译成英语。在用于英语之前，这需要更多的修正。

function ago($d) {
$ts = time() - strtotime(str_replace("-","/",$d));

        if($ts>315360000) $val = round($ts/31536000,0).' year';
        else if($ts>94608000) $val = round($ts/31536000,0).' years';
        else if($ts>63072000) $val = ' two years';
        else if($ts>31536000) $val = ' a year';

        else if($ts>24192000) $val = round($ts/2419200,0).' month';
        else if($ts>7257600) $val = round($ts/2419200,0).' months';
        else if($ts>4838400) $val = ' two months';
        else if($ts>2419200) $val = ' a month';


        else if($ts>6048000) $val = round($ts/604800,0).' week';
        else if($ts>1814400) $val = round($ts/604800,0).' weeks';
        else if($ts>1209600) $val = ' two weeks';
        else if($ts>604800) $val = ' a week';

        else if($ts>864000) $val = round($ts/86400,0).' day';
        else if($ts>259200) $val = round($ts/86400,0).' days';
        else if($ts>172800) $val = ' two days';
        else if($ts>86400) $val = ' a day';

        else if($ts>36000) $val = round($ts/3600,0).' year';
        else if($ts>10800) $val = round($ts/3600,0).' years';
        else if($ts>7200) $val = ' two years';
        else if($ts>3600) $val = ' a year';

        else if($ts>600) $val = round($ts/60,0).' minute';
        else if($ts>180) $val = round($ts/60,0).' minutes';
        else if($ts>120) $val = ' two minutes';
        else if($ts>60) $val = ' a minute';

        else if($ts>10) $val = round($ts,0).' second';
        else if($ts>2) $val = round($ts,0).' seconds';
        else if($ts>1) $val = ' two seconds';
        else $val = $ts.' a second';


        return $val;
    }

我使用以下功能几年了。它运行得很好:

function timeDifference($timestamp)
{
    $otherDate=$timestamp;
    $now=@date("Y-m-d H:i:s");

    $secondDifference=@strtotime($now)-@strtotime($otherDate);
    $extra="";
    if ($secondDifference == 2592000) { 
    // months 
    $difference = $secondDifference/2592000; 
    $difference = round($difference,0); 
    if ($difference>1) { $extra="s"; } 
    $difference = $difference." month".$extra." ago"; 
}else if($secondDifference > 2592000)
    {$difference=timestamp($timestamp);} 
elseif ($secondDifference >= 604800) { 
    // weeks 
    $difference = $secondDifference/604800; 
    $difference = round($difference,0); 
    if ($difference>1) { $extra="s"; } 
    $difference = $difference." week".$extra." ago"; 
} 
elseif ($secondDifference >= 86400) { 
    // days 
    $difference = $secondDifference/86400; 
    $difference = round($difference,0); 
    if ($difference>1) { $extra="s"; } 
    $difference = $difference." day".$extra." ago"; 
} 
elseif ($secondDifference >= 3600) { 
    // hours 

    $difference = $secondDifference/3600; 
    $difference = round($difference,0); 
    if ($difference>1) { $extra="s"; } 
    $difference = $difference." hour".$extra." ago"; 
} 
elseif ($secondDifference < 3600) { 
    // hours 
    // for seconds (less than minute)
    if($secondDifference<=60)
    {       
        if($secondDifference==0)
        {
            $secondDifference=1;
        }
        if ($secondDifference>1) { $extra="s"; }
        $difference = $secondDifference." second".$extra." ago"; 

    }
    else
    {

$difference = $secondDifference/60; 
        if ($difference>1) { $extra="s"; }else{$extra="";}
        $difference = round($difference,0); 
        $difference = $difference." minute".$extra." ago"; 
    }
} 

$FinalDifference = $difference; 
return $FinalDifference;
}