function timeAgo($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 );

    $msg = null;
    // Seconds
    if($seconds <= 60){
        if ($seconds == 1)
            $msg = "1 секунду";
        else if ( $seconds < 5 )
            $msg = "$seconds секунды";
        else if ( $seconds <= 20 )
            $msg = "$seconds секунд";
        else if ( $seconds == 21 )
            $msg = "21 секунду";
        else if ( $seconds <= 24 )
            $msg = "$seconds секунды";
        else if ( $seconds <= 29 )
            $msg = "$seconds секунд";
        else if ( $seconds == 30 )
            $msg = "30 секунд";
        ...
    }

...
    return msg;
}

char sec_0[] = "секунд";
char sec_1[] = "секунда";
char sec_2[] = "секунду";
......

char * str_sec[60] = {sec_0,sec_2, .....} ;

char * get_str_sec(int sec)
{
   return str_sec[sec];
}