diff --git a/admin/calendar.html b/admin/calendar.html
index 6b6cc6e4ce1..32184ae2d56 100644
--- a/admin/calendar.html
+++ b/admin/calendar.html
@@ -66,7 +66,7 @@
         </div>
         <div>
           <nobr><input type="radio" id="timezone2" name="forcetimezone" value="force" <?php if(!empty($CFG->forcetimezone)) echo 'checked="checked"';?> /> <label for="timezone2"><?php print_string('timezoneisforcedto', 'admin'); ?></label>
-          <?php choose_from_menu($presets, 'dstpreset', (empty($CFG->forcetimezone) ? 0 : $CFG->forcetimezone), get_string('choose').'...', 'form.timezone2.checked=\'checked\''); ?>
+          <?php choose_from_menu($presets, 'timezonepreset', (empty($CFG->forcetimezone) ? 0 : $CFG->forcetimezone), get_string('choose').'...', 'form.timezone2.checked=\'checked\''); ?>
           </nobr>
         </div>
         <?php } ?>
diff --git a/admin/calendar.php b/admin/calendar.php
index a5e17c1d5bd..f87fac2418d 100644
--- a/admin/calendar.php
+++ b/admin/calendar.php
@@ -38,14 +38,14 @@
             set_config('calendar_adminseesall', intval($form->adminseesallcourses) != 0);
             unset($SESSION->cal_courses_shown);
         }
-        if(isset($form->dstforusers)) {
-            if($form->dstforusers == 'force') {
-                $preset = optional_param('dstpreset', 0, PARAM_INT);
+        if(isset($form->forcetimezone)) {
+            if($form->forcetimezone == 'force') {
+                $preset = optional_param('timezonepreset', 0, PARAM_INT);
             }
             else {
                 $preset = 0;
             }
-            set_config('calendar_dstforusers', $preset);
+            set_config('forcetimezone', $preset);
         }
         if(isset($form->startwday)) {
             $startwday = intval($form->startwday);
@@ -85,7 +85,7 @@
 
     // Populate some variables we 're going to need in calendar.html
 
-    $presets = get_records('dst_preset');
+    $presets = get_records('timezone');
     if(!empty($presets)) {
         foreach($presets as $id => $preset) {
             $presets[$id] = $preset->name;
diff --git a/lib/moodlelib.php b/lib/moodlelib.php
index 553011ab09a..bd1bddac70a 100644
--- a/lib/moodlelib.php
+++ b/lib/moodlelib.php
@@ -108,6 +108,7 @@ define('PARAM_CLEANFILE',0x0200);
 define('PARAM_ALPHANUM', 0x0400);  //numbers or letters only
 define('PARAM_BOOL',     0x0800);  //convert to value 1 or 0 using empty()
 define('PARAM_CLEANHTML',0x1000);  //actual HTML code that you want cleaned and slashes removed
+define('PARAM_ALPHAEXT', 0x2000);  // PARAM_ALPHA plus the chars in quotes: "/-_" allowed
 
 /**
  * Definition of page types
@@ -207,6 +208,10 @@ function clean_param($param, $options) {
         $param = eregi_replace('[^A-Za-z0-9]', '', $param);
     }
 
+    if ($options & PARAM_ALPHAEXT) {     // Remove everything not a-zA-Z/_-
+        $param = eregi_replace('[^a-zA-Z/_-]', '', $param);
+    }
+
     if ($options & PARAM_BOOL) {         // Convert to 1 or 0
         $param = empty($param) ? 0 : 1;
     }
@@ -863,17 +868,19 @@ function get_user_timezone_preset() {
         return $preset;
     }
 
-    if (empty($CFG->calendar_dstforusers)) {
-        if (empty($USER->dstpreset)) {
+    if (empty($CFG->forcetimezone)) {
+        if (empty($USER->timezonename)) {
             return NULL;
         }
-        $presetid = $USER->dstpreset;
+        $presetname = $USER->timezonename;
 
     } else {
-        $presetid = $CFG->calendar_dstforusers;
+        $presetname = $CFG->forcetimezone;
     }
 
-    $preset = get_record('dst_preset', 'id', $presetid);
+    $presetrecords = get_records('timezone', 'name', $presetname);
+    
+    //print_object($presetrecords);
 
     if(!empty($USER)) {
         if(empty($USER->dstoffsets)) {
@@ -895,84 +902,6 @@ function get_user_timezone_preset() {
     return $preset;
 }
 
-// This should be obsolete, but let's leave it inside a while longer
-/*
-function dst_update_preset($dstpreset, $time = NULL) {
-
-    // What's the date according to our user?
-    if($time === NULL) {
-        $time = time();
-    }
-    $date = usergetdate($time);
-
-    $changes = dst_changes_for_year($date['year'], $dstpreset);
-
-    if($changes['activate'] == 0 && $changes['deactivate'] == 0) {
-        // This timezone doesn't have DST, so don't do anything
-        return $dstpreset;
-    }
-    else if($changes['activate'] == 0) {
-        // There's only the "deactivate" time
-        if($time >= $changes['deactivate']) {
-            $nextchanges = dst_changes_for_year($date['year'] + 1, $dstpreset);
-            $dstpreset->next_change = min($nextchanges['activate'], $nextchanges['deactivate']);
-            $dstpreset->current_offset = 0;
-        }
-        return $dstpreset;
-    }
-    else if($changes['deactivate'] == 0) {
-        // There's only the "activate" time
-        if($time >= $changes['activate']) {
-            $nextchanges = dst_changes_for_year($date['year'] + 1, $dstpreset);
-            $dstpreset->next_change = min($nextchanges['activate'], $nextchanges['deactivate']);
-            $dstpreset->current_offset = $dstpreset->apply_offset;
-        }
-    }
-    else if($changes['activate'] < $changes['deactivate']) {
-        // Northern hemisphere
-
-        if ($time < $changes['activate']) {
-            // DST has not been turned on this year
-            $dstpreset->next_change = $changes['activate'];
-            $dstpreset->current_offset = 0;
-    
-        } else if($time < $changes['deactivate']) {
-            // DST is on at this time
-            $dstpreset->next_change = $changes['deactivate'];
-            $dstpreset->current_offset = $dstpreset->apply_offset;
-    
-        } else {
-            // DST has already been turned off; we are nearing the end of the year
-            $nextchanges = dst_changes_for_year($date['year'] + 1, $dstpreset);
-            $dstpreset->next_change = $nextchanges['activate'];
-            $dstpreset->current_offset = 0;
-        }
-    }
-    else if($changes['activate'] > $changes['deactivate']) {
-        // Southern hemisphere
-
-        if ($time < $changes['deactivate']) {
-            // DST is still on from the previous year
-            $dstpreset->next_change = $changes['deactivate'];
-            $dstpreset->current_offset = $dstpreset->apply_offset;
-
-        } else if($time < $changes['activate']) {
-            // DST is off at this time
-            $dstpreset->next_change = $changes['activate'];
-            $dstpreset->current_offset = 0;
-    
-        } else {
-            // DST has been turned on; we are nearing the end of the year
-            $nextchanges = dst_changes_for_year($date['year'] + 1, $dstpreset);
-            $dstpreset->next_change = $nextchanges['deactivate'];
-            $dstpreset->current_offset = $dstpreset->apply_offset;
-        }
-    }
-
-    return $dstpreset;
-}
-*/
-
 function dst_offset_for_year($year, $dstpreset) {
     return $dstpreset->apply_offset * MINSECS;
 }
diff --git a/user/edit.html b/user/edit.html
index 845c67686f8..11387de7618 100644
--- a/user/edit.html
+++ b/user/edit.html
@@ -240,7 +240,7 @@ if (isadmin()) {
             $presetarray = array('0' => get_string('notimezone', 'calendar'));
             if(!empty($presets)) {
                 foreach($presets as $preset) {
-                    $presetarray[$preset->id] = $preset->name;
+                    $presetarray[$preset->name] = $preset->name;
                 }
                 choose_from_menu ($presetarray, 'timezonename', empty($user->timezonename) ? 0 : $user->timezonename, '');
             }
@@ -249,7 +249,7 @@ if (isadmin()) {
             }
         }
         else {
-            $preset = get_record('timezone', 'id', $CFG->forcetimezone);
+            $preset = get_record('timezone', 'name', $CFG->forcetimezone);
             if(empty($preset)) {
                 print_string('nodstpresets');
             }
diff --git a/user/edit.php b/user/edit.php
index f895f1cd484..a2d68849425 100644
--- a/user/edit.php
+++ b/user/edit.php
@@ -102,7 +102,9 @@
         $usernew->autosubscribe = clean_param($usernew->autosubscribe, PARAM_INT);
         $usernew->htmleditor    = clean_param($usernew->htmleditor,    PARAM_INT);
         $usernew->emailstop     = clean_param($usernew->emailstop,     PARAM_INT);
-        
+
+        $usernew->timezonename  = clean_param($usernew->timezonename,  PARAM_ALPHAEXT);
+
         foreach ($usernew as $key => $data) {
             $usernew->$key = addslashes(clean_text(stripslashes($usernew->$key), FORMAT_MOODLE));
         }