diff --git a/app/helpers/DateHelper.php b/app/helpers/DateHelper.php
new file mode 100644
index 000000000..f9f063ffc
--- /dev/null
+++ b/app/helpers/DateHelper.php
@@ -0,0 +1,78 @@
+<?php
+
+/**
+ * Return a human-readable week
+ * @return string
+ */
+function getDays() {
+    return array(
+        1 => t('Monday'),
+        2 => t('Tuesday'),
+        3 => t('Wednesday'),
+        4 => t('Thursday'),
+        5 => t('Friday'),
+        6 => t('Saturday'),
+        7 => t('Friday'));
+}
+/**
+ * Return a human-readable year
+ * @return string
+ */
+function getMonths() {
+    return array(
+        1 => t('January'),
+        2 => t('February'),
+        3 => t('March'),
+        4 => t('April'),
+        5 => t('May'),
+        6 => t('June'),
+        7 => t('July'),
+        8 => t('August'),
+        9 => t('September'),
+        10 => t('October'),
+        11 => t('November'),
+        12 => t('December'));
+}
+
+/**
+ * Return a human-readable date 
+ *
+ * @param timestamp $string
+ * @return string
+ */
+function prepareDate($time, $hours = true) {
+    $dotw = getDays();
+        
+    $moty = getMonths();
+
+    $today = strtotime(date('M j, Y'));
+    $reldays = ($time - $today)/86400;
+
+    if ($reldays >= 0 && $reldays < 1) {
+        $date = t('Today');
+    } else if ($reldays >= 1 && $reldays < 2) {
+        $date = t('Tomorrow');
+    } else if ($reldays >= -1 && $reldays < 0) {
+        $date = t('Yesterday');
+    } else {
+
+        if (abs($reldays) < 7) {
+            if ($reldays > 0) {
+                $reldays = floor($reldays);
+                $date = 'In ' . $reldays . ' '.t('day') . ($reldays != 1 ? 's' : '');
+            } else {
+                $reldays = abs(floor($reldays));
+                $date = t(' %d days ago', $reldays);
+            }
+        } else {
+            $date = $dotw[date('N',$time ? $time : time())] .', '.date('j',$time ? $time : time()).' '.$moty[date('n',$time ? $time : time())] ;
+            if (abs($reldays) > 182)
+                $date .= date(', Y',$time ? $time : time());
+        }
+    }
+    if($hours)
+        $date .= ' - '. date('H:i', $time);
+    
+    if($time)
+        return $date;
+}
diff --git a/app/helpers/StringHelper.php b/app/helpers/StringHelper.php
new file mode 100644
index 000000000..d927e5401
--- /dev/null
+++ b/app/helpers/StringHelper.php
@@ -0,0 +1,216 @@
+<?php
+
+/**
+ * Prepare the string (add the a to the links and show the smileys)
+ *
+ * @param string $string
+ * @return string
+ */
+function prepareString($string) {
+    $smileys = 
+        array(
+            // HFR icons
+            ":'\("  => 'cry.gif',
+            ':love:'=> 'love.gif',
+            'O:\)'  => 'ange.gif',
+            'O:-\)' => 'ange.gif',
+            ':redface:' => 'redface.gif',
+            ':petrus:'  => 'petrus75.gif',
+            
+            // famfamfam icons
+            ':\)\)' => 'grin.png',
+            ':\)'   => 'smiley.png',
+            ':-\)'  => 'smiley.png',
+            ':\('   => 'sad.png',
+            ':o'    => 'shocked.png',
+            ':O'    => 'shocked.png',
+            ':D'    => 'grin.png',
+            ':d'    => 'grin.png',
+            ':p'    => 'tongue.png',
+            ':P'    => 'tongue.png',
+            ':-P'   => 'tongue.png',
+            ';D'    => 'wink.png',
+            ';d'    => 'wink.png',
+            ';\)'   => 'wink.png',
+            '\^\^'  => 'happy.png',
+            '\(k\)' => 'heart.png',
+            'B\)'   => 'cool.png',
+            ':s'    => 'confused.png',
+            ':S'    => 'confused.png',
+            ':\/'   => 'wondering.png',
+            ':evil:'=> 'evil.png',
+            ":\|"   => 'neutral.png',
+            
+            // Meme icons
+            ':okay:'        => 'okay.gif',
+            ':trolldad:'    => 'trolldad.png',
+            ':epic:'        => 'epic.png',
+            ':aloneyeah:'   => 'aloneyeah.png',
+            ':fapfap:'      => 'fapfap.png',
+            ':megusta:'     => 'gusta.png',
+            ':trollface:'   => 'trollface.png',
+            ':troll:'       => 'trollface.png',
+            ':lol:'         => 'trollol.png',
+            ':genius:'      => 'genius.png',
+        );
+
+    //replace begin by www
+    $string = preg_replace_callback(
+            '/(^|\s|>)(www.[^<> \n\r]+)/ix', function ($match) {
+                //print '<br />preg[1]';\system\Debug::dump($match);
+                if (strlen($match[2])>0) {
+                    return stripslashes($match[1].'<a href=\"http://'.$match[2].'\" target=\"_blank\">'.$match[2].'</a>');
+                } else {
+                    return $match[2];
+                }
+            }, ' ' . $string
+    );
+
+    //replace  begin by http - https (before www)
+    $string = preg_replace_callback(
+            '/(?(?=<a[^>]*>.+<\/a>)(?:<a[^>]*>.+<\/a>)|([^="\'])((?:https?):\/\/([^<> \n\r]+)))/ix', function ($match) {
+                if (isset($match[2]) && strlen($match[2])>0) {
+                    return stripslashes($match[1].'<a href=\"'.$match[2].'\" target=\"_blank\">'.$match[3].'</a>');
+                } else {
+                    return $match[0];
+                }
+            }, ' ' . $string
+    );
+
+    // Twitter hashtags
+    $string = preg_replace_callback(
+        "/ #[a-zA-Z0-9_-]*/", function ($match) {
+            return
+                ' <a class="twitter hastag" href="http://twitter.com/search?q='.
+                    urlencode(trim($match[0])).
+                    '&src=hash" target="_blank">'.
+                    trim($match[0]).
+                '</a>';
+        }, ' ' . $string
+    );
+
+    $string = preg_replace_callback(
+        "/ @[a-zA-Z0-9_-]*/", function ($match) {
+            return
+                ' <a class="twitter at" href="http://twitter.com/'.
+                    trim($match[0]).
+                    '" target="_blank">'.
+                    trim($match[0]).
+                '</a>';
+      }, ' ' . $string
+    );
+
+    //remove all scripts
+    $string = preg_replace_callback(
+            '#<[/]?script[^>]*>#is', function ($match) {
+                return '';
+            }, ' ' . $string
+    );
+    //remove all iframe
+    $string = preg_replace_callback(
+            '#<[/]?iframe[^>]*>#is', function ($match) {
+                return '';
+            }, ' ' . $string
+    );
+   
+    // We add some smileys...
+    $conf = new \system\Conf();
+    $theme = $conf->getServerConfElement('theme');
+    
+    $path = BASE_URI . 'themes/' . $theme . '/img/smileys/';
+
+    foreach($smileys as $key => $value) {
+        $replace = ' <img class="smiley" alt="smiley" src="'.$path.$value.'">';
+        $string = preg_replace('/(^|[ ])('.$key.')/',  $replace, $string);
+    }
+    
+    return trim($string);
+}
+
+
+/**
+ * Fix self-closing tags
+ */
+function fixSelfClosing($string) {
+    return preg_replace_callback('/<([^\s<]+)\/>/',
+        function($match) {
+            return '<'.$match[1].'></'.$match[1].'>';
+        }
+        , $string);
+}
+
+/**
+ * Remove the content, body and html tags
+ */
+function cleanHTMLTags($string) {
+    return str_replace(
+        array(
+            '<content type="html">',
+            '<html xmlns="http://jabber.org/protocol/xhtml-im">',
+            '<body xmlns="http://www.w3.org/1999/xhtml">',
+            '</body>',
+            '</html>', 
+            '</content>'),
+        '',
+        $string);
+}
+
+/**
+ * Return an array of informations from a XMPP uri
+ */
+function explodeURI($uri) {
+    $arr = parse_url(urldecode($uri));
+    $result = array();
+    
+    if(isset($arr['query'])) {
+        $query = explode(';', $arr['query']);
+
+
+        foreach($query as $elt) {
+            if($elt != '') {
+                list($key, $val) = explode('=', $elt);
+                $result[$key] = $val;
+            }
+        }
+
+        $arr = array_merge($arr, $result);
+    }
+    
+    return $arr;
+
+}
+
+/*
+ * Echap the JID 
+ */
+function echapJid($jid)
+{
+    return str_replace(' ', '\40', $jid);
+}
+
+/**
+ * Return a URIfied string
+ * @param string
+ * @return string
+ */
+function stringToUri($url) {
+    $url = utf8_decode($url);
+    $url = strtolower(strtr($url, utf8_decode('ÀÁÂÃÄÅàáâãäåÒÓÔÕÖØòóôõöøÈÉÊËèéêëÇçÌÍÎÏìíîïÙÚÛÜùúûüÿÑñ()[]\'"~$&%*@ç!?;,:/\^¨€{}<>|+- '),  'aaaaaaaaaaaaooooooooooooeeeeeeeecciiiiiiiiuuuuuuuuynn    --      c  ---    e      --'));
+    $url = str_replace(' ', '', $url);
+    $url = str_replace('---', '-', $url);
+    $url = str_replace('--', '-', $url);
+    $url = trim($url,'-');
+    return $url;
+}
+
+/**
+ * Return a human readable filesize
+ * @param string size in bytes
+ * @return string
+ */
+function sizeToCleanSize($size)
+{
+    $units = array( 'B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB');
+    $power = $size > 0 ? floor(log($size, 1024)) : 0;
+    return number_format($size / pow(1024, $power), 2, '.', ',') . ' ' . $units[$power];
+}
diff --git a/app/helpers/TimezoneHelper.php b/app/helpers/TimezoneHelper.php
new file mode 100644
index 000000000..45d1cae25
--- /dev/null
+++ b/app/helpers/TimezoneHelper.php
@@ -0,0 +1,63 @@
+<?php
+
+/*
+ * Get the timezone list
+ */
+ function getTimezoneList()
+ {
+    return array(
+        'Etc/GMT+12' => -12.00,
+        'Etc/GMT+11' => -11.00,
+        'Etc/GMT+10' => -10.00,
+        'Etc/GMT+9' => -9.00,
+        'Etc/GMT+8' => -8.00,
+        'Etc/GMT+7' => -7.00,
+        'Etc/GMT+6' => -6.00,
+        'Etc/GMT+5' => -5.00,
+        'America/Caracas' => -4.30,
+        'Etc/GMT+4' => -4.00,
+        'America/St_Johns' => -3.30,
+        'Etc/GMT+3' => -3.00,
+        'Etc/GMT+2' => -2.00,
+        'Etc/GMT+1' => -1.00,
+        'Etc/GMT' => 0,
+        'Etc/GMT-1' => 1.00,
+        'Etc/GMT-2' => 2.00,
+        'Etc/GMT-3' => 3.00,
+        'Asia/Tehran' => 3.30,
+        'Etc/GMT-4' => 4.00,
+        'Etc/GMT-5' => 5.00,
+        'Asia/Kolkata' => 5.30,
+        'Asia/Katmandu' => 5.45,
+        'Etc/GMT-6' => 6.00,
+        'Asia/Rangoon' => 6.30,
+        'Etc/GMT-7' => 7.00,
+        'Etc/GMT-8' => 8.00,
+        'Etc/GMT-9' => 9.00,
+        'Australia/Darwin' => 9.30,
+        'Etc/GMT-10' => 10.00,
+        'Etc/GMT-11' => 11.00,
+        'Etc/GMT-12' => 12.00,
+        'Etc/GMT-13' => 13.00);
+ }
+ 
+
+/*
+ * Get the user local timezone
+ */
+function getLocalTimezone()
+{
+    date_default_timezone_set('UTC');
+    $iTime = time();
+    $arr = localtime($iTime);
+    $arr[5] += 1900;
+    $arr[4]++;
+    $iTztime = gmmktime($arr[2], $arr[1], $arr[0], $arr[4], $arr[3], $arr[5]);
+    $offset = doubleval(($iTztime-$iTime)/(60*60));
+    $zonelist = getTimezoneList();
+
+    $index = array_keys($zonelist, $offset);
+    if(sizeof($index)!=1)
+        return false;
+    return $index[0];
+}