diff --git a/htdocs/comm/action/index.php b/htdocs/comm/action/index.php
index 2474349e2d2..2754c44b465 100644
--- a/htdocs/comm/action/index.php
+++ b/htdocs/comm/action/index.php
@@ -69,13 +69,14 @@ $action=GETPOST('action','alpha');
 //$year=GETPOST("year");
 $year=GETPOST("year","int")?GETPOST("year","int"):date("Y");
 $month=GETPOST("month","int")?GETPOST("month","int"):date("m");
+$week=GETPOST("week","int")?GETPOST("week","int"):date("W");
 $day=GETPOST("day","int")?GETPOST("day","int"):0;
 $pid=GETPOST("projectid","int")?GETPOST("projectid","int"):0;
 $status=GETPOST("status");
 $maxprint=GETPOST("maxprint");
 
 if (GETPOST('viewcal'))  { $action='show_month'; $day=''; }         // View by month
-if (GETPOST('viewweek')) { $action='show_week'; $week=date("W"); }     // View by week
+if (GETPOST('viewweek')) { $action='show_week'; $week=date("W"); $day=date("d");}     // View by week
 if (GETPOST('viewday'))  { $action='show_day'; $day=date("d"); }    // View by day
 
 $langs->load("other");
@@ -145,7 +146,7 @@ if (empty($action) || $action=='show_month')
 }
 if ($action=='show_week')
 {
-	
+	  	
 }
 if ($action=='show_day')
 {
@@ -181,7 +182,7 @@ if ($socid)   $param.="&socid=".$socid;
 if ($showbirthday) $param.="&showbirthday=1";
 if ($pid)     $param.="&projectid=".$pid;
 if (GETPOST("type"))   $param.="&type=".GETPOST("type");
-if ($action == 'show_day') $param.='&action='.$action;
+if ($action == 'show_day' || $action == 'show_week') $param.='&action='.$action;
 if ($maxprint) $param.="&maxprint=on";
 
 // Show navigation bar
@@ -194,7 +195,10 @@ if (empty($action) || $action=='show_month')
 }
 if ($action=='show_week')
 {
-	
+	$nav ="<a href=\"?year=".$prev_year."&amp;month=".$prev_month."&amp;week=".$prev_week."&amp;day=".$prev_day."&amp;region=".$region.$param."\">".img_previous($langs->trans("Previous"))."</a>\n";
+	$nav.=" <span id=\"month_name\">".dol_print_date(dol_mktime(0,0,0,$month,1,$year),"%Y").", ".$langs->trans("Week")." ".$week;
+	$nav.=" </span>\n";
+	$nav.="<a href=\"?year=".$next_year."&amp;month=".$next_month."&amp;week=".$next_week."&amp;day=".$next_day."&amp;region=".$region.$param."\">".img_next($langs->trans("Next"))."</a>\n";
 }
 if ($action=='show_day')
 {
@@ -516,7 +520,7 @@ if (empty($action) || $action == 'show_month')		// View by month
 	}
 	echo "</table>\n";
 }
-elseif ($action == 'show_week') // View by day
+elseif ($action == 'show_week') // View by week
 {
 	print $langs->trans("FeatureNotYetAvailable"); //Work in progress...
 }
@@ -569,9 +573,8 @@ function show_day_events($db, $day, $month, $year, $monthshown, $style, &$eventa
 	global $cachethirdparty, $cachecontact;
 
 	if ($_GET["maxprint"] == 'on') $maxPrint=0;   // Force to remove limits
-
+	
 	$curtime = dol_mktime (0, 0, 0, $month, $day, $year);
-
 	print '<table class="nobordernopadding" width="100%">';
 	print '<tr style="background: #EEEEEE"><td align="left" nowrap="nowrap">';
 	print '<a href="'.DOL_URL_ROOT.'/comm/action/index.php?';
diff --git a/htdocs/lib/date.lib.php b/htdocs/lib/date.lib.php
index e96e1731747..9aa122b8607 100644
--- a/htdocs/lib/date.lib.php
+++ b/htdocs/lib/date.lib.php
@@ -1,6 +1,7 @@
 <?php
 /* Copyright (C) 2004-2010 Laurent Destailleur  <eldy@users.sourceforge.net>
  * Copyright (C) 2005-2008 Regis Houssin        <regis@dolibarr.fr>
+ * Copyright (C) 2011	   Juanjo Menent        <jmenent@2byte.es>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -198,6 +199,51 @@ function dol_get_next_month($month, $year)
 	return array('year' => $next_year, 'month' => $next_month);
 }
 
+/**	Return previous week
+ * 	@param		week	Week
+ *	@param		year	Year
+ *	@return		array	Previous year,month,week
+ */
+function dol_get_prev_week($week, $year)
+{
+	if ($week == 1)
+	{
+		$prev_week  = 52;
+		$prev_month = 12;
+		$prev_year  = $year - 1;
+	}
+	else
+	{
+		$prev_week	= $week-1;
+		$str_tmp = str_pad($prev_week, 2, 0, STR_PAD_LEFT); 
+		$prev_month = date('n', strtotime($year.'-W'.$str_tmp));
+		$prev_year  = $year;
+	}
+	return array('year' => $prev_year, 'month'=>$prev_month, 'week' => $prev_week);
+}
+ 
+/**	Return next week
+ *	@param		week	Week
+ *	@param		year	Year
+ *	@return		array	Next year,month,week
+ */
+function dol_get_next_week($week, $year)
+{
+	if ($week == 52)
+	{
+		$next_week  = 1;
+		$next_month = 1;
+		$next_year  = $year + 1;
+	}
+	else
+	{
+		$next_week  = $week + 1;
+		$str_tmp = str_pad($next_week, 2, 0, STR_PAD_LEFT); 
+		$next_month = date('n', strtotime($year.'-W'.$str_tmp));
+		$next_year  = $year;
+	}
+	return array('year' => $next_year, 'month'=>$next_month, 'week' => $next_week);
+}
 
 /**	Return GMT time for first day of a month or year
  *	@param		year		Year
@@ -238,6 +284,72 @@ function dol_get_last_day($year,$month=12,$gm=false)
 	return $datelim;
 }
 
+/**	Return  first day of week for a week
+ *	@param		day			Day
+ * 	@param		month		Month
+ * 	@param		gm			False = Return date to compare with server TZ, True to compare with GM date.
+ *	@return		Timestamp	Date for first day of week
+ */
+function dol_get_first_day_of_week($day,$month,$year,$gm=false) 
+{
+	$date=dol_mktime(0,0,0,$month,$day,$year,$gm);
+	
+	if (isset($conf->global->MAIN_START_WEEK))
+	{
+		if ($conf->global->MAIN_START_WEEK==1)
+		{
+			$getdate = getdate($date);
+ 
+    		// How many days ahead monday are we?
+    		switch ( $getdate['wday'] ) 
+    		{
+        		case 0: // we are on sunday
+            		$days = 6;
+            		break;
+ 
+        		default: // any other day
+            		$days = $getdate['wday']-1;
+            		break;
+    		}
+ 
+    		$seconds = $days*24*60*60;
+    		$monday = date($getdate[0])-$seconds;
+ 
+    		return $monday;
+ 		
+		}
+		else
+		{
+        	$getdate = getdate($date);
+    		// substact as many days as days ahead sunday we are
+    		$seconds = $getdate['wday']*24*60*60;
+    		$sunday = date($getdate[0])-$seconds;
+ 
+    		return $sunday;
+		}
+	}
+	else 
+	{
+		$getdate = getdate($date);
+
+    	// How many days ahead monday are we?
+    	switch ( $getdate['wday'] ) 
+    	{
+        	case 0: // we are on sunday
+            	$days = 6;
+            	break;
+            	
+	        default: // any other day
+    	        $days = $getdate['wday']-1;
+        	    break;
+    	}
+ 
+    	$seconds = $days*24*60*60;
+    	$monday = date($getdate[0])-$seconds;
+ 
+    	return $monday;
+	}
+}
 
 /**
  *	Fonction retournant le nombre de jour fieries samedis et dimanches entre 2 dates entrees en timestamp