diff --git a/airtime_mvc/application/controllers/ApiController.php b/airtime_mvc/application/controllers/ApiController.php
index dfd05339a..2fb9173b5 100644
--- a/airtime_mvc/application/controllers/ApiController.php
+++ b/airtime_mvc/application/controllers/ApiController.php
@@ -352,7 +352,10 @@ class ApiController extends Zend_Controller_Action
         $now = new DateTime($today_timestamp);
         $end_timestamp = $now->add(new DateInterval("PT2H"));
         $end_timestamp = $end_timestamp->format("Y-m-d H:i:s");
-        $this->view->shows = Application_Model_Show::getShows($today_timestamp, $end_timestamp, $excludeInstance=NULL, $onlyRecord=TRUE);
+        
+        $this->view->shows = Application_Model_Show::getShows(Application_Model_DateHelper::ConvertToUtcDateTime($today_timestamp, date_default_timezone_get()), 
+                                                                Application_Model_DateHelper::ConvertToUtcDateTime($end_timestamp, date_default_timezone_get()),
+                                                                $excludeInstance=NULL, $onlyRecord=TRUE);
 
 
         $this->view->is_recording = false;
diff --git a/airtime_mvc/application/controllers/ScheduleController.php b/airtime_mvc/application/controllers/ScheduleController.php
index 329264855..194fc0df0 100644
--- a/airtime_mvc/application/controllers/ScheduleController.php
+++ b/airtime_mvc/application/controllers/ScheduleController.php
@@ -68,8 +68,8 @@ class ScheduleController extends Zend_Controller_Action
 
     public function eventFeedAction()
     {
-        $start = $this->_getParam('start', null);
-		$end = $this->_getParam('end', null);
+        $start = new DateTime($this->_getParam('start', null));
+        $end = new DateTime($this->_getParam('end', null));
 
 		$userInfo = Zend_Auth::getInstance()->getStorage()->read();
         $user = new Application_Model_User($userInfo->id);
@@ -355,11 +355,14 @@ class ScheduleController extends Zend_Controller_Action
             $this->view->show_error = true;
             return false;
         }
+        
         $start_timestamp = $show->getShowStart();
 		$end_timestamp = $show->getShowEnd();
 
         //check to make sure show doesn't overlap.
-        if(Application_Model_Show::getShows($start_timestamp, $end_timestamp, array($showInstanceId))) {
+        if(Application_Model_Show::getShows(new DateTime($start_timestamp, new DateTimeZone("UTC")), 
+                                            new DateTime($end_timestamp, new DateTimeZone("UTC")), 
+                                            array($showInstanceId))) {
             $this->view->error = "cannot schedule an overlapping show.";
             return;
         }
@@ -563,7 +566,7 @@ class ScheduleController extends Zend_Controller_Action
         foreach($js as $j){
             $data[$j["name"]] = $j["value"];
         }
-    Logging::log("id:".$data['add_show_id']);
+        
         $show = new Application_Model_Show($data['add_show_id']);
 
         $startDateModified = true;
diff --git a/airtime_mvc/application/models/Preference.php b/airtime_mvc/application/models/Preference.php
index af7ea4924..7be719613 100644
--- a/airtime_mvc/application/models/Preference.php
+++ b/airtime_mvc/application/models/Preference.php
@@ -119,12 +119,34 @@ class Application_Model_Preference
         $view->headTitle(self::GetHeadTitle());
     }
 
-    public static function SetShowsPopulatedUntil($timestamp) {
-        self::SetValue("shows_populated_until", $timestamp);
+    /**
+     * Set the furthest date that a never-ending show 
+     * should be populated until.
+     * 
+     * @param DateTime $dateTime
+     *        A row from cc_show_days table
+     */ 
+    public static function SetShowsPopulatedUntil($dateTime) {
+        self::SetValue("shows_populated_until", $dateTime->format("Y-m-d"));
     }
 
+    /**
+     * Get the furthest date that a never-ending show 
+     * should be populated until.
+     *
+     * Returns null if the value hasn't been set, otherwise returns
+     * a DateTime object representing the date. 
+     * 
+     * @return DateTime (in UTC Timezone)
+     */
     public static function GetShowsPopulatedUntil() {
-        return self::GetValue("shows_populated_until");
+        $date = self::GetValue("shows_populated_until");
+        
+        if ($date == ""){
+            return null;
+        } else {
+            return new DateTime($date, new DateTimeZone("UTC"));
+        }
     }
 
     public static function SetDefaultFade($fade) {
diff --git a/airtime_mvc/application/models/RabbitMq.php b/airtime_mvc/application/models/RabbitMq.php
index bc5eaa1f7..8504565eb 100644
--- a/airtime_mvc/application/models/RabbitMq.php
+++ b/airtime_mvc/application/models/RabbitMq.php
@@ -74,13 +74,13 @@ class Application_Model_RabbitMq
         $EXCHANGE = 'airtime-show-recorder';
         $channel->exchange_declare($EXCHANGE, 'direct', false, true);
     
-        $now = new DateTime("@".time());
-        $end_timestamp = new DateTime("@".(time() + 3600*2));
+        $now = new DateTime("@".time()); //in UTC timezone
+        $end_timestamp = new DateTime("@".(time() + 3600*2)); //in UTC timezone
 
         $temp['event_type'] = $event_type;
         $temp['server_timezone'] = Application_Model_Preference::GetTimezone();
         if($event_type = "update_schedule"){
-            $temp['shows'] = Application_Model_Show::getShows($now->format("Y-m-d H:i:s"), $end_timestamp->format("Y-m-d H:i:s"), $excludeInstance=NULL, $onlyRecord=TRUE);
+            $temp['shows'] = Application_Model_Show::getShows($now, $end_timestamp, $excludeInstance=NULL, $onlyRecord=TRUE);
         }
         $data = json_encode($temp);
         $msg = new AMQPMessage($data, array('content_type' => 'text/plain'));
diff --git a/airtime_mvc/application/models/Show.php b/airtime_mvc/application/models/Show.php
index c3d913050..a3413b854 100644
--- a/airtime_mvc/application/models/Show.php
+++ b/airtime_mvc/application/models/Show.php
@@ -736,7 +736,6 @@ class Application_Model_Show {
      */
     public static function create($data)
     {
-
         $startDateTime = new DateTime($data['add_show_start_date']." ".$data['add_show_start_time']);
         $utcStartDateTime = clone $startDateTime;
         $utcStartDateTime->setTimezone(new DateTimeZone('UTC'));
@@ -888,7 +887,7 @@ class Application_Model_Show {
                 $showHost->save();
             }
         }
-
+        
         Application_Model_Show::populateShowUntil($showId);
         Application_Model_RabbitMq::PushSchedule();
         return $showId;
@@ -910,14 +909,14 @@ class Application_Model_Show {
         if (is_null($p_dateTime)) {
             $date = Application_Model_Preference::GetShowsPopulatedUntil();
 
-            if ($date == "") {
+            if (is_null($date)) {
                 $p_dateTime = new DateTime("now", new DateTimeZone('UTC'));
-                Application_Model_Preference::SetShowsPopulatedUntil($p_dateTime->format("Y-m-d"));
+                Application_Model_Preference::SetShowsPopulatedUntil($p_dateTime);
             } else {
-                $p_dateTime = new DateTime($date, new DateTimeZone('UTC'));
+                $p_dateTime = $date;
             }
         }
-
+        
         $sql = "SELECT * FROM cc_show_days WHERE show_id = $p_showId";
         $res = $CC_DBC->GetAll($sql);
 
@@ -937,8 +936,7 @@ class Application_Model_Show {
      * @param DateTime $p_dateTime
      *        DateTime object in UTC time.
      */ 
-    private static function populateShow($p_showRow, $p_dateTime) {
-                
+    private static function populateShow($p_showRow, $p_dateTime) {                
         if($p_showRow["repeat_type"] == -1) {
             Application_Model_Show::populateNonRepeatingShow($p_showRow, $p_dateTime);
         }
@@ -1033,7 +1031,7 @@ class Application_Model_Show {
     private static function populateRepeatingShow($p_showRow, $p_dateTime, $p_interval)
     {
         global $CC_DBC;
-                
+                               
         $show_id = $p_showRow["show_id"];
         $next_pop_date = $p_showRow["next_pop_date"];
         $first_show = $p_showRow["first_show"]; //non-UTC
@@ -1059,10 +1057,11 @@ class Application_Model_Show {
 
         $date = new Application_Model_DateHelper();
         $currentUtcTimestamp = $date->getUtcTimestamp();
-        
-        while($utcStartDateTime->getTimestamp() <= $p_dateTime->getTimestamp() && 
+                                
+        while($utcStartDateTime->getTimestamp()
+                <= $p_dateTime->getTimestamp() && 
                 ($utcStartDateTime->getTimestamp() < strtotime($last_show) || is_null($last_show))) {
-                    
+                                        
             $utcStart = $utcStartDateTime->format("Y-m-d H:i:s");
             $sql = "SELECT timestamp '{$utcStart}' + interval '{$duration}'";
             $utcEndDateTime = new DateTime($CC_DBC->GetOne($sql), new DateTimeZone("UTC"));
@@ -1136,12 +1135,12 @@ class Application_Model_Show {
     }
 
     /**
-     * Get all the show instances in the given time range.
+     * Get all the show instances in the given time range (inclusive).
      *
-     * @param string $start_timestamp
-     *      In the format "YYYY-MM-DD HH:mm:ss".  This time is inclusive.
-     * @param string $end_timestamp
-     *      In the format "YYYY-MM-DD HH:mm:ss". This time is inclusive.
+     * @param DateTime $start_timestamp
+     *      In UTC time.
+     * @param DateTime $end_timestamp
+     *      In UTC time.
      * @param unknown_type $excludeInstance
      * @param boolean $onlyRecord
      * @return array
@@ -1153,7 +1152,7 @@ class Application_Model_Show {
         $showsPopUntil = Application_Model_Preference::GetShowsPopulatedUntil();
 
         //if application is requesting shows past our previous populated until date, generate shows up until this point.
-        if ($showsPopUntil == "" || strtotime($showsPopUntil) < strtotime($end_timestamp)) {
+        if (is_null($showsPopUntil) || $showsPopUntil->getTimestamp() < $end_timestamp->getTimestamp()) {
             Application_Model_Show::populateAllShowsInRange($showsPopUntil, $end_timestamp);
             Application_Model_Preference::SetShowsPopulatedUntil($end_timestamp);
         }
@@ -1164,16 +1163,18 @@ class Application_Model_Show {
             LEFT JOIN cc_show ON cc_show.id = cc_show_instances.show_id";
 
         //only want shows that are starting at the time or later.
+        $start_string = $start_timestamp->format("Y-m-d H:i:s");
+        $end_string = $end_timestamp->format("Y-m-d H:i:s");
         if ($onlyRecord) {
 
-            $sql = $sql." WHERE (starts >= '{$start_timestamp}' AND starts < timestamp '{$end_timestamp}')";
+            $sql = $sql." WHERE (starts >= '{$start_string}' AND starts < timestamp '{$end_string}')";
             $sql = $sql." AND (record = 1)";
         }
         else {
 
-            $sql = $sql." WHERE ((starts >= '{$start_timestamp}' AND starts < '{$end_timestamp}')
-                OR (ends > '{$start_timestamp}' AND ends <= '{$end_timestamp}')
-                OR (starts <= '{$start_timestamp}' AND ends >= '{$end_timestamp}'))";
+            $sql = $sql." WHERE ((starts >= '{$start_string}' AND starts < '{$end_string}')
+                OR (ends > '{$start_string}' AND ends <= '{$end_string}')
+                OR (starts <= '{$start_string}' AND ends >= '{$end_string}'))";
         }
 
 
@@ -1206,25 +1207,28 @@ class Application_Model_Show {
     /**
      * Generate all the repeating shows in the given range.
      *
-     * @param string $p_startTimestamp
-     *         In the format "YYYY-MM-DD HH:mm:ss"
-     * @param string $p_endTimestamp
-     *         In the format "YYYY-MM-DD HH:mm:ss"
+     * @param DateTime $p_startTimestamp
+     *         In UTC format.
+     * @param DateTime $p_endTimestamp
+     *         In UTC format.
      */
     public static function populateAllShowsInRange($p_startTimestamp, $p_endTimestamp)
     {
         global $CC_DBC;
-
-        if ($p_startTimestamp != "") {
+        
+        $endTimeString = $p_endTimestamp->format("Y-m-d H:i:s");
+        if (!is_null($p_startTimestamp)) {
+            $startTimeString = $p_startTimestamp->format("Y-m-d H:i:s");
             $sql = "SELECT * FROM cc_show_days
                     WHERE last_show IS NULL
-                    OR first_show < '{$p_endTimestamp}' AND last_show > '{$p_startTimestamp}'";
+                    OR first_show < '{$endTimeString}' AND last_show > '{$startTimeString}'";
         }
         else {
-            $today_timestamp = date("Y-m-d");
+            $today_timestamp = new DateTime("now", new DateTimeZone("UTC"));
+            $today_timestamp_string = $today_timestamp->format("Y-m-d H:i:s");
             $sql = "SELECT * FROM cc_show_days
                     WHERE last_show IS NULL
-                    OR first_show < '{$p_endTimestamp}' AND last_show > '{$today_timestamp}'";
+                    OR first_show < '{$endTimeString}' AND last_show > '{$today_timestamp_string}'";
         }
 
         $res = $CC_DBC->GetAll($sql);
@@ -1236,19 +1240,17 @@ class Application_Model_Show {
 
     /**
      *
-     * @param string $start
-     *      In the format "YYYY-MM-DD HH:mm:ss"
-     * @param string $end
-     *         In the format "YYYY-MM-DD HH:mm:ss"
+     * @param DateTime $start
+     *          -in UTC time
+     * @param DateTime $end
+     *          -in UTC time
      * @param boolean $editable
      */
     public static function getFullCalendarEvents($start, $end, $editable=false)
     {
         $events = array();
 
-        $start_range = new DateTime($start);
-        $end_range = new DateTime($end);
-        $interval = $start_range->diff($end_range);
+        $interval = $start->diff($end);
         $days =  $interval->format('%a');
 
         $shows = Application_Model_Show::getShows($start, $end);
diff --git a/airtime_mvc/application/models/ShowInstance.php b/airtime_mvc/application/models/ShowInstance.php
index a5092ebdd..e26532a93 100644
--- a/airtime_mvc/application/models/ShowInstance.php
+++ b/airtime_mvc/application/models/ShowInstance.php
@@ -51,11 +51,21 @@ class Application_Model_ShowInstance {
         return $show->getDbGenre();
     }
 
+    /**
+     * Return the start time of the Show (UTC time)
+     * @return string in format "Y-m-d H:i:s" (PHP time notation)
+     * TODO: make this function return a DateTime object instead.
+     */
     public function getShowStart()
     {
         return $this->_showInstance->getDbStarts();
     }
 
+    /**
+     * Return the end time of the Show (UTC time)
+     * @return string in format "Y-m-d H:i:s" (PHP time notation)
+     * TODO: make this function return a DateTime object instead.
+     */
     public function getShowEnd()
     {
         return $this->_showInstance->getDbEnds();
@@ -184,16 +194,18 @@ class Application_Model_ShowInstance {
 
         $sql = "SELECT timestamp '{$starts}' + interval '{$deltaDay} days' + interval '{$hours}:{$mins}'";
         $new_starts = $CC_DBC->GetOne($sql);
+        $newStartsDateTime = new DateTime($new_starts, new DateTimeZone("UTC"));
 
         $sql = "SELECT timestamp '{$ends}' + interval '{$deltaDay} days' + interval '{$hours}:{$mins}'";
         $new_ends = $CC_DBC->GetOne($sql);
+        $newEndsDateTime = new DateTime($new_ends, new DateTimeZone("UTC"));
 
-        $newStartsDateTime = new DateTime($new_starts, new DateTimeZone("UTC"));
+        
         if($today_timestamp > $newStartsDateTime->getTimestamp()) {
             return "Can't move show into past";
         }
 
-        $overlap = Application_Model_Show::getShows($new_starts, $new_ends, array($this->_instanceId));
+        $overlap = Application_Model_Show::getShows($newStartsDateTime, $newEndsDateTime, array($this->_instanceId));
         
         if(count($overlap) > 0) {
             return "Should not overlap shows";
@@ -247,6 +259,7 @@ class Application_Model_ShowInstance {
 
         //only need to check overlap if show increased in size.
         if(strtotime($new_ends) > strtotime($ends)) {
+            //TODO --martin
             $overlap =  Application_Model_Show::getShows($ends, $new_ends);
 
             if(count($overlap) > 0) {
diff --git a/airtime_mvc/application/models/tests/populator.php b/airtime_mvc/application/models/tests/populator.php
index 6d70e1fbb..bf3f5b27b 100644
--- a/airtime_mvc/application/models/tests/populator.php
+++ b/airtime_mvc/application/models/tests/populator.php
@@ -66,7 +66,7 @@ function createTestShow($showNumber, $showTime, $duration = "1:00")
     //echo "show created, ID: $showId\n";
 
     // populating the show with a playlist
-    $instances = Application_Model_Show::getShows($showTime->format("Y-m-d H:i:s"), $showTime->format("Y-m-d H:i:s"));
+    $instances = Application_Model_Show::getShows($showTime, $showTime);
     $instance = array_pop($instances);
     $show = new Application_Model_ShowInstance($instance["instance_id"]);
     //echo "Adding playlist to show instance ".$show->getShowInstanceId()."\n";