diff --git a/main/inc/lib/main_api.lib.php b/main/inc/lib/main_api.lib.php
index d5b8adec54..60f51ff2e4 100755
--- a/main/inc/lib/main_api.lib.php
+++ b/main/inc/lib/main_api.lib.php
@@ -2360,8 +2360,11 @@ function api_item_property_update($_course, $tool, $item_id, $lastedit_type, $us
 	$start_visible 	= ($start_visible == 0) ? '0000-00-00 00:00:00' : $start_visible;
 	$end_visible 	= ($end_visible == 0) ? '0000-00-00 00:00:00' : $end_visible;
 	$to_filter 		= '';
-	$time 			= time();
-	$time 			= date('Y-m-d H:i:s', $time);
+	//$time 			= time();
+	//$time 			= date('Y-m-d H:i:s', $time);
+	//According to http://support.chamilo.org/projects/chamilo-18/wiki/Date_and_time_management
+	//@todo fix $start_visible and $end_visible
+	$time			= api_get_utc_datetime();
 
 	if (!empty($session_id)) {
 		$session_id = intval($session_id);
diff --git a/main/work/work.lib.php b/main/work/work.lib.php
index 06c0d39994..c1f7abc5cd 100755
--- a/main/work/work.lib.php
+++ b/main/work/work.lib.php
@@ -258,9 +258,6 @@ function convert_date_to_array($date, $group) {
 	foreach ($time_parts as $item) {
 		$time_parts_tmp[] = intval($item);
 	}
-
-
-
 	list($data[$group.'[year]'], $data[$group.'[month]'], $data[$group.'[day]']) = $date_parts_tmp;
 	list($data[$group.'[hour]'], $data[$group.'[minute]']) = $time_parts_tmp;
 	return $data;
@@ -296,6 +293,9 @@ function create_group_date_select($prefix = '') {
 * @param $dateFormatLong - date format
 * @param $origin - typically empty or 'learnpath'
 */
+
+	
+			
 function display_student_publications_list($work_dir, $sub_course_dir, $currentCourseRepositoryWeb, $link_target_parameter, $dateFormatLong, $origin, $add_in_where_query = '') {
 	global $timeNoSecFormat, $dateFormatShort, $gradebook, $_user;
 	// Database table names
@@ -480,10 +480,12 @@ function display_student_publications_list($work_dir, $sub_course_dir, $currentC
 
 					if ($row['view_properties'] == '1') {
 						if ($homework['expires_on'] != '0000-00-00 00:00:00') {
+							$homework['expires_on'] = api_get_local_time($homework['expires_on']);
 							$there_is_a_expire_date = true;
 							$form_folder -> addGroup(create_group_date_select(), 'expires', get_lang('ExpiresAt'));
 						}
 						if ($homework['ends_on'] != '0000-00-00 00:00:00') {
+							$homework['ends_on'] = api_get_local_time($homework['ends_on']);
 							$there_is_a_end_date = true;
 							$form_folder -> addGroup(create_group_date_select(), 'ends', get_lang('EndsAt'));
 						}
@@ -501,13 +503,16 @@ function display_student_publications_list($work_dir, $sub_course_dir, $currentC
 		  	                         </div>	');
 
 		  	            $form_folder -> addElement('html', '<div id="options" style="display: none;">');
+		  	            
 						if (empty($default)) {
-							$default = date('Y-m-d 12:00:00');
+							$default = api_get_local_time();
 						}
 
 						$parts = split(' ', $default);
+						
 						list($d_year, $d_month, $d_day) = split('-', $parts[0]);
 						list($d_hour, $d_minute) = split(':', $parts[1]);
+						
 						if ((int)$row['weight'] == 0) {
 							$form_folder -> addElement('checkbox', 'make_calification', null, get_lang('MakeQualifiable'), 'onclick="javascript: if(this.checked){document.getElementById(\'option3\').style.display = \'block\';}else{document.getElementById(\'option3\').style.display = \'none\';}"');
 							$form_folder -> addElement('html', '<div id=\'option3\' style="display:none">');
@@ -517,7 +522,7 @@ function display_student_publications_list($work_dir, $sub_course_dir, $currentC
 						}
 
 						if ($homework['expires_on'] == '0000-00-00 00:00:00') {
-							$homework['expires_on'] = date('Y-m-d H:i:s');
+							$homework['expires_on'] = api_get_local_time();
 							$there_is_a_expire_date = true;
 							$form_folder -> addElement('checkbox', 'enableExpiryDate',null,get_lang('EnableExpiryDate'), 'onclick="javascript: if(this.checked){document.getElementById(\'option1\').style.display = \'block\';}else{document.getElementById(\'option1\').style.display = \'none\';}"');
 							$form_folder -> addElement('html', '<div id=\'option1\' style="display:none">');
@@ -525,7 +530,7 @@ function display_student_publications_list($work_dir, $sub_course_dir, $currentC
 							$form_folder -> addElement('html', '</div>');
 						}
 						if ($homework['ends_on'] == '0000-00-00 00:00:00') {
-							$homework['ends_on'] = date('Y-m-d H:i:s');
+							$homework['ends_on'] = api_get_local_time();
 							$there_is_a_end_date = true;
 							$form_folder -> addElement('checkbox', 'enableEndDate', null, get_lang('EnableEndDate'), 'onclick="javascript: if(this.checked){document.getElementById(\'option2\').style.display = \'block\';}else{document.getElementById(\'option2\').style.display = \'none\';}"');
 							$form_folder -> addElement('html', '<div id=\'option2\' style="display:none">');
@@ -534,19 +539,17 @@ function display_student_publications_list($work_dir, $sub_course_dir, $currentC
 						}
 
 						$form_folder -> addRule(array('expires', 'ends'), get_lang('DateExpiredNotBeLessDeadLine'), 'comparedate');
-
 						$form_folder -> addElement('html', '</div>');
 					}
 
 					$form_folder -> addElement('style_submit_button', 'submit', get_lang('ModifyDirectory'), 'class="save"');
-					if ($there_is_a_end_date) {
-						$end_date_array = convert_date_to_array($homework['ends_on'], 'ends');
+					if ($there_is_a_end_date) {						
+						$end_date_array = convert_date_to_array($homework['ends_on'], 'ends');						
 						$defaults = array_merge($defaults, $end_date_array);
 					}
 					if ($there_is_a_expire_date) {
 						$expires_date_array = convert_date_to_array($homework['expires_on'], 'expires');
 						$defaults = array_merge($defaults, $expires_date_array);
-
 					}
 					if (!empty($row['qualification'])) {
 						$defaults = array_merge($defaults, array('qualification[qualification]' => $row['qualification']));
@@ -579,12 +582,12 @@ function display_student_publications_list($work_dir, $sub_course_dir, $currentC
 								if ($row['view_properties'] == '1') {
 									$sql_add_publication = "UPDATE ".$work_table." SET has_properties  = '".$row['has_properties'].  "', view_properties=1 where id ='".$row['id']."'";
 									Database::query($sql_add_publication);
-									$expires_query = ' SET expires_on = '."'".($there_is_a_expire_date ? get_date_from_group('expires') : '0000-00-00 00:00:00')."'".',';
-									$ends_query =    ' ends_on = '."'".($there_is_a_end_date ? get_date_from_group('ends') : '0000-00-00 00:00:00')."'";
+									$expires_query = ' SET expires_on = '."'".($there_is_a_expire_date ? api_get_utc_datetime(get_date_from_group('expires')) : '0000-00-00 00:00:00')."'".',';
+									$ends_query =    ' ends_on = '."'".($there_is_a_end_date ? api_get_utc_datetime(get_date_from_group('ends')) : '0000-00-00 00:00:00')."'";
 									Database::query('UPDATE '.$work_assigment.$expires_query.$ends_query.' WHERE id = '."'".$row['has_properties']."'");
 								} elseif ($row['view_properties'] == '0') {
 									if ($_POST['enableExpiryDate'] == '1') {
-										$expires_query = ' SET expires_on = '."'".($there_is_a_expire_date ? get_date_from_group('expires') : '0000-00-00 00:00:00')."'";
+										$expires_query = ' SET expires_on = '."'".($there_is_a_expire_date ? api_get_utc_datetime(get_date_from_group('expires')) : '0000-00-00 00:00:00')."'";
 										//$ends_query =    ' ends_on = '."'".($there_is_a_end_date ? get_date_from_group('ends') : '0000-00-00 00:00:00')."'";
 										Database::query('UPDATE '.$work_assigment.$expires_query.' WHERE id = '."'".$row['has_properties']."'");
 										$sql_add_publication = "UPDATE ".$work_table." SET has_properties  = '".$row['has_properties'].  "', view_properties=1 where id ='".$row['id']."'";
@@ -592,7 +595,7 @@ function display_student_publications_list($work_dir, $sub_course_dir, $currentC
 									}
 									if ($_POST['enableEndDate'] == '1') {
 										//$expires_query = ' SET expires_on = '."'".($there_is_a_expire_date ? get_date_from_group('expires') : '0000-00-00 00:00:00')."'".',';
-										$ends_query =    ' SET ends_on = '."'".($there_is_a_end_date ? get_date_from_group('ends') : '0000-00-00 00:00:00')."'";
+										$ends_query =    ' SET ends_on = '."'".($there_is_a_end_date ? api_get_utc_datetime(get_date_from_group('ends')) : '0000-00-00 00:00:00')."'";
 										Database::query('UPDATE '.$work_assigment.$ends_query.' WHERE id = '."'".$row['has_properties']."'");
 										$sql_add_publication = "UPDATE ".$work_table." SET has_properties  = '".$row['has_properties'].  "', view_properties=1 where id ='".$row['id']."'";
 										Database::query($sql_add_publication);
@@ -722,7 +725,7 @@ function display_student_publications_list($work_dir, $sub_course_dir, $currentC
 			}
 
 			if ($direc_date != '' && $direc_date != '0000-00-00 00:00:00') {
-				$direc_date_local = api_get_local_time($direc_date, null, date_default_timezone_get());
+				$direc_date_local = api_get_local_time($direc_date);
 				$row[] = date_to_str_ago($direc_date_local).'<br /><span class="dropbox_date">'.api_format_date($direc_date_local).'</span>';
 			} else {
 				$direc_date_local = '0000-00-00 00:00:00';
@@ -784,14 +787,14 @@ function display_student_publications_list($work_dir, $sub_course_dir, $currentC
 				$row[] = '<a href="download.php?file='.$url.'">'.build_document_icon_tag('file', substr(basename($work->url), 13)).'</a>';
 				$row[] = '<a href="download.php?file='.$url.'"'.$class.'><img src="../img/filesave.gif" style="float:right;" alt="'.get_lang('Save').'" title="'.get_lang('Save').'" />'.$work->title.'</a><br />'.$work->description;
 				$row[] = display_user_link_work($row2['insert_user_id'], $work->author).$qualification_string; // $work->author;
-
-				$work_sent_date_local = api_get_local_time($work->sent_date, null, date_default_timezone_get());
+			
+				$work_sent_date_local = api_get_local_time($work->sent_date);				
 				$row[] = date_to_str_ago($work_sent_date_local).$add_string.'<br /><span class="dropbox_date">'.api_format_date($work_sent_date_local).'</span>';
 
 				if ($is_allowed_to_edit) {
 
 					$action = '';
-					$action .= '<a href="'.api_get_self().'?'.api_get_cidreq().'&curdirpath='.urlencode($my_sub_dir).'&amp;origin='.$origin.'&gradebook='.$gradebook.'&amp;edit='.$work->id.'&gradebook='.Security::remove_XSS($_GET['gradebook']).'&amp;parent_id='.$work->parent_id.'" title="'.get_lang('Score').'"  ><img src="../img/qualify.png" alt="'.get_lang('Score').'" title="'.get_lang('Score').'"></a>';
+					$action .= '<a href="'.api_get_self().'?'.api_get_cidreq().'&curdirpath='.urlencode($my_sub_dir).'&amp;origin='.$origin.'&gradebook='.$gradebook.'&amp;edit='.$work->id.'&gradebook='.Security::remove_XSS($_GET['gradebook']).'&amp;parent_id='.$work->parent_id.'" title="'.get_lang('Modify').'"  ><img src="../img/edit.gif" alt="'.get_lang('Modify').'" title="'.get_lang('Modify').'"></a>';
 					$action .= '<a href="'.api_get_self().'?'.api_get_cidreq().'&curdirpath='.urlencode($my_sub_dir).'&amp;origin='.$origin.'&gradebook='.$gradebook.'&amp;delete='.$work->id.'" onclick="javascript:if(!confirm('."'".addslashes(api_htmlentities(get_lang('ConfirmYourChoice'),ENT_QUOTES))."'".')) return false;" title="'.get_lang('WorkDelete').'" >'.Display::return_icon('delete.gif', get_lang('WorkDelete')).'</a>';
 					$action .= '<a href="'.api_get_self().'?'.api_get_cidreq().'&curdirpath='.urlencode($my_sub_dir).'&amp;origin='.$origin.'&gradebook='.$gradebook.'&amp;move='.$work->id.'" title="'.get_lang('Move').'"><img src="../img/deplacer_fichier.gif" border="0" title="'.get_lang('Move').'" alt="'.get_lang('Move').'" /></a>';
 					if ($work->accepted == '1') {
diff --git a/main/work/work.php b/main/work/work.php
index 3ee4f38a48..ad103aeba7 100755
--- a/main/work/work.php
+++ b/main/work/work.php
@@ -535,14 +535,14 @@ if (!empty($_REQUEST['new_dir'])) {
 				require_once api_get_path(SYS_CODE_PATH).'calendar/agenda.inc.php';
 				require_once api_get_path(SYS_CODE_PATH).'resourcelinker/resourcelinker.inc.php';
 				$course = isset($course_info) ? $course_info : null;
-				$date = date('Y-m-d H:i:s');
+				$date = api_get_utc_datetime();
 				$title = Security::remove_XSS($_POST['new_dir']);
 				if (!empty($_POST['type1'])) {
-					$date = get_date_from_select('expires');
+					$date = api_get_utc_datetime(get_date_from_select('expires'));
 					$title = sprintf(get_lang('HandingOverOfTaskX'),Security::remove_XSS($_POST['new_dir']));
 				}
 				$content = '<a href="'.api_get_self().'?'.api_get_cidreq().'&amp;curdirpath='.substr(Security::remove_XSS($dir_name_sql), 1).'" >'.Security::remove_XSS($_POST['new_dir']).'</a> - '.Security::remove_XSS($_POST['description']);
-				error_log($date);
+				
 				$agenda_id = agenda_add_item($course, $title, $content, $date, $date, array('GROUP:'.$toolgroup), 0);
 			}
 			$sql_add_publication = "INSERT INTO " . $work_table . " SET " .
@@ -554,7 +554,7 @@ if (!empty($_REQUEST['new_dir'])) {
 									   accepted		= '1',
 									   filetype 	= 'folder',
 									   post_group_id = '".$toolgroup."',
-									   sent_date	= NOW(),
+									   sent_date	= '".api_get_utc_datetime()."',
 									   qualification	= '".(($_POST['qualification_value']!='') ? Database::escape_string($_POST['qualification_value']) : '') ."',
 									   parent_id	= '',
 									   qualificator_id	= '',
@@ -582,8 +582,8 @@ if (!empty($_REQUEST['new_dir'])) {
 
 				$enable_calification = isset($_POST['enable_calification']) ? (int)$_POST['enable_calification'] : null;
 				$sql_add_homework = "INSERT INTO $TSTDPUBASG SET " .
-														   "expires_on         = '".((isset($_POST['type1']) && $_POST['type1']==1) ? get_date_from_select('expires') : '0000-00-00 00:00:00'). "',
-													        ends_on        = '".((isset($_POST['type2']) && $_POST['type2']==1) ? get_date_from_select('ends') : '0000-00-00 00:00:00')."',
+														   "expires_on         = '".((isset($_POST['type1']) && $_POST['type1']==1) ? api_get_utc_datetime(get_date_from_select('expires')) : '0000-00-00 00:00:00'). "',
+													        ends_on        = '".((isset($_POST['type2']) && $_POST['type2']==1) ? api_get_utc_datetime(get_date_from_select('ends')) : '0000-00-00 00:00:00')."',
 										                    add_to_calendar  = '$agenda_id',
 										                    enable_qualification = '".$enable_calification."',
 										                    publication_id = '".$id."'";
@@ -595,7 +595,7 @@ if (!empty($_REQUEST['new_dir'])) {
 			} else {
 
 				$sql_add_homework = "INSERT INTO $TSTDPUBASG SET " .
-														   "expires_on         = '0000-00-00 00:00:00',
+														   "expires_on     = '0000-00-00 00:00:00',
 													        ends_on        = '0000-00-00 00:00:00',
 										                    add_to_calendar  = '$agenda_id',
 										                    enable_qualification = '".(isset($_POST['enable_calification'])?(int)$_POST['enable_calification']:'')."',
@@ -885,7 +885,7 @@ if ($ctok == $_POST['sec_token']) { //check the token inserted into the form
 				if (!Database::num_rows($result)) {
 					Database::query("ALTER TABLE " . $work_table . " ADD sent_date DATETIME NOT NULL");
 				}
-				$current_date = date('Y-m-d H:i:s');
+				$current_date = api_get_utc_datetime();
 				$parent_id = '';
 				$active = '';
 				$user_id = api_get_user_id();
@@ -943,7 +943,7 @@ if ($ctok == $_POST['sec_token']) { //check the token inserted into the form
 			if (!Database::num_rows($result)) {
 				Database::query("ALTER TABLE " . $work_table . " ADD sent_date DATETIME NOT NULL");
 			}
-			$current_date = date('Y-m-d H:i:s');
+			$current_date = api_get_utc_datetime();
 			$sql = "INSERT INTO  " . $work_table . "
 					        	SET url        	= '" . $url . "',
 					            title       	= '" . Database::escape_string($title) . "',
@@ -992,7 +992,7 @@ if ($ctok == $_POST['sec_token']) { //check the token inserted into the form
 				if($is_allowed_to_edit && ($_POST['qualification']!='')) {
 					$add_to_update = ',qualificator_id ='."'".api_get_user_id()."',";
 					$add_to_update .= 'qualification ='."'".Database::escape_string($_POST['qualification'])."',";
-					$add_to_update .= 'date_of_qualification ='."'".date('Y-m-d H:i:s')."'";
+					$add_to_update .= 'date_of_qualification ='."'".api_get_utc_datetime()."'";
 				}
 
 				if ((int)$_POST['qualification'] > (int)$_POST['qualification_over']) {
@@ -1074,7 +1074,7 @@ if (!empty($_POST['submitWork']) && !empty($succeed) && !$id) {
 			$emailbody = get_lang('SendMailBody')."\n".get_lang('CourseName')." : ".$_course['name']."\n";
 			$emailbody .= get_lang('WorkName')." : ".substr($my_cur_dir_path, 0, -1)."\n";
 			$emailbody .= get_lang('UserName')." : ".$currentUserFirstName .' '.$currentUserLastName ."\n";
-			$emailbody .= get_lang('DateSent')." : ".date('d/m/Y H:i')."\n";
+			$emailbody .= get_lang('DateSent')." : ".api_get_local_time()."\n";
 			$emailbody .= get_lang('FileName')." : ".$title."\n\n".get_lang('DownloadLink')."\n";
 			$emailbody .= api_get_path(WEB_CODE_PATH)."work/work.php?".api_get_cidreq()."&amp;curdirpath=".$my_cur_dir_path."\n\n" . api_get_setting('administratorName') . " " . api_get_setting('administratorSurname') . "\n" . get_lang('Manager') . " " . api_get_setting('siteName') . "\n" . get_lang('Email') . " : " . api_get_setting('emailAdministrator');
 			// Here we are forming one large header line
@@ -1084,7 +1084,7 @@ if (!empty($_POST['submitWork']) && !empty($succeed) && !$id) {
 			$emailbody_user = get_lang('Dear')." ".$currentUserFirstName .' '.$currentUserLastName ."\n";
 			$emailbody_user .= get_lang('MessageConfirmSendingOfTask')."\n".get_lang('CourseName')." : ".$_course['name']."\n";
 			$emailbody_user .= get_lang('WorkName')." : ".substr($my_cur_dir_path, 0, -1)."\n";
-			$emailbody_user .= get_lang('DateSent')." : ".date('d/m/Y H:i')."\n";
+			$emailbody_user .= get_lang('DateSent')." : ".api_get_local_time()."\n";
 			$emailbody_user .= get_lang('FileName')." : ".$title."\n\n".api_get_setting('administratorName')." ".api_get_setting('administratorSurname') . "\n" . get_lang('Manager') . " " . api_get_setting('siteName') . "\n" . get_lang('Email') . " : " . api_get_setting('emailAdministrator');;
 
 			//Mail to user
@@ -1125,15 +1125,18 @@ if ($is_special > 0) {
 	$has_expiry_date = true;
 
 	if ($homework['expires_on'] != '0000-00-00 00:00:00' || $homework['ends_on'] != '0000-00-00 00:00:00') {
-		$time_now = convert_date_to_number(date('Y-m-d H:i:s'));
-		$time_expires = convert_date_to_number($homework['expires_on']);
-		$time_ends = convert_date_to_number($homework['ends_on']);
-		$difference = $time_expires - $time_now;
-		$difference2 = $time_ends - $time_now;
-		if ($homework['expires_on'] != '0000-00-00 00:00:00' && $difference < 0) {
+		$time_now		= convert_date_to_number(api_get_local_time());
+		$time_expires 	= convert_date_to_number(api_get_local_time($homework['expires_on']));
+		$time_ends 		= convert_date_to_number(api_get_local_time($homework['ends_on']));
+				
+		$difference 	= $time_expires - $time_now;		
+		
+		$difference2 	= $time_ends - $time_now;
+		if ($homework['expires_on'] != '0000-00-00 00:00:00' && $difference < 0) {			
 			$has_expired = true;
 		}
 		if ($homework['ends_on'] != '0000-00-00 00:00:00' && $difference2 < 0) {
+			
 			$has_ended = true;
 		}
 		if ($homework['expires_on'] == '0000-00-00 00:00:00') {
@@ -1143,8 +1146,8 @@ if ($is_special > 0) {
 			//@todo fix me
 			define('ASSIGNMENT_EXPIRES', $time_expires);
 		}
-		$ends_on 	= api_convert_and_format_date($homework['ends_on'], null, date_default_timezone_get());
-		$expires_on = api_convert_and_format_date($homework['expires_on'], null, date_default_timezone_get());
+		$ends_on 	= api_convert_and_format_date($homework['ends_on']);
+		$expires_on = api_convert_and_format_date($homework['expires_on']);
 
 		if ($has_ended) {
 			display_action_links($cur_dir_path, $always_show_tool_options, true);
@@ -1486,7 +1489,8 @@ function make_checkbox($name, $checked = '') {
 function draw_date_picker($prefix, $default = '') {
 	//$default = 2008-10-01 10:00:00
 	if (empty($default)) {
-		$default = date('Y-m-d H:i:s');
+		//$default = date('Y-m-d H:i:s');		
+		$default = api_get_local_time();
 	}
 	$parts = split(' ', $default);
 	list($d_year, $d_month, $d_day) = split('-', $parts[0]);