diff --git a/html/inc/boinc_db.inc b/html/inc/boinc_db.inc
index 7231d36377..5d299efcd3 100644
--- a/html/inc/boinc_db.inc
+++ b/html/inc/boinc_db.inc
@@ -464,6 +464,14 @@ class BoincProfile {
         $db = BoincDb::get();
         return $db->lookup('profile', 'BoincProfile', $clause);
     }
+    static function lookup_userid($userid) {
+        $db = BoincDb::get();
+        return $db->lookup('profile', 'BoincProfile', 'userid='.$userid);
+    }
+    function update($clause) {
+        $db = BoincDb::get();
+        return $db->update_aux('profile', $clause.' where userid='.$this->userid);
+    }
     static function update_aux($clause) {
         $db = BoincDb::get();
         return $db->update_aux('profile', $clause);
@@ -480,6 +488,10 @@ class BoincProfile {
         $db = BoincDb::get();
         return $db->enum_fields('profile', 'BoincProfile', $fields, $where_clause, $order_clause);
     }
+    function delete() {
+        $db = BoincDb::get();
+        return $db->delete_aux('profile', 'userid='.$this->userid);
+    }
     static function delete_aux($clause) {
         $db = BoincDb::get();
         return $db->delete_aux('profile', $clause);
diff --git a/html/inc/db_conn.inc b/html/inc/db_conn.inc
index 852a9160d5..b7fe126539 100644
--- a/html/inc/db_conn.inc
+++ b/html/inc/db_conn.inc
@@ -242,6 +242,13 @@ class DbConn {
             return mysql_error($this->db_conn);
         }
     }
+    function base_errno() {
+        if (MYSQLI) {
+            return $this->db_conn->errno;
+        } else {
+            return mysql_errno($this->db_conn);
+        }
+    }
     function table_exists($table_name) {
         $result = $this->do_query("show tables from DBNAME like '$table_name'");
         if (!$result) error_page("database error on query $query");
diff --git a/html/inc/uotd.inc b/html/inc/uotd.inc
index bf0d83bb44..00e9ab3e56 100644
--- a/html/inc/uotd.inc
+++ b/html/inc/uotd.inc
@@ -1,7 +1,7 @@
 <?php
 // This file is part of BOINC.
 // http://boinc.berkeley.edu
-// Copyright (C) 2008 University of California
+// Copyright (C) 2015 University of California
 //
 // BOINC is free software; you can redistribute it and/or modify it
 // under the terms of the GNU Lesser General Public License
@@ -47,7 +47,7 @@ function show_uotd($profile) {
 // return the last UOTD profile, or null
 //
 function get_current_uotd() {
-    $profiles = BoincProfile::enum(null, "ORDER BY uotd_time DESC LIMIT 1");
+    $profiles = BoincProfile::enum("uotd_time is not NULL and uotd_time>0", "ORDER BY uotd_time DESC LIMIT 1");
     if (sizeof($profiles)) {
         return $profiles[0];
     }
@@ -56,10 +56,10 @@ function get_current_uotd() {
 
 // Select a (possibly new) UOTD
 //
-function select_uotd() {
+function select_uotd($force_new = false) {
     echo gmdate("F d Y", time())." UTC: Starting\n";
     $current_uotd = get_current_uotd();
-    if ($current_uotd) {
+    if ($current_uotd && !$force_new) {
         $assigned = getdate($current_uotd->uotd_time);
         $now = getdate(time());
         if ($assigned['mday'] == $now['mday']) {
@@ -69,60 +69,82 @@ function select_uotd() {
             exit();
         }
     }
+    if ($force_new) {
+        echo "Forcing new UOTD\n";
+    }
 
     // get a list of profiles that have been 'approved' for UOTD,
     // using a project-specific query if supplied in project.inc
     //
     if (function_exists('uotd_candidates_query')) {
         $query = uotd_candidates_query();
+        echo "using project supplied candidates_query\n";
     } else {
         $query = default_uotd_candidates_query();
+        echo "using default candidates_query\n";
     }
-    $result = _mysql_query($query);
+    $db = BoincDb::get();
+    $result = $db->do_query($query);
 
     // If the number of approved profiles dips below a threshold,
     // email the sys admin every time we pick a new one.
     //
     if (defined('UOTD_ADMIN_EMAIL')
         && $result
-        && _mysql_num_rows($result) < UOTD_THRESHOLD
+        && $result->num_rows < UOTD_THRESHOLD
     ) {
+        echo "approved candidates for UOTD under UOTD_THRESHOLD\n";
         $u = new BoincUser;
         $u->email_addr = UOTD_ADMIN_EMAIL;
         $u->name = "UOTD admin";
         send_email($u,
             PROJECT . ": User of the Day pool is running low!",
             "The pool of approved candidates for User of the Day has".
-            " reached your assigned threshold: there are now only " . _mysql_num_rows($result) . " approved users.\n\n".
+            " reached your assigned threshold: there are now only " . $result->num_rows . " approved users.\n\n".
             "To approve more candidates for User of the Day,".
             " go to the " . PROJECT . " administration page and click \"Screen user profiles\""
         );
     }
 
-    if ($result && _mysql_num_rows($result) == 0) {
+    if ($result && $result->num_rows == 0) {
+        echo "no new verified profile found, selecting old UOTD that was shown least recently\n";
+        $result->free();
         // If all verified profiles have been selected as UOTD,
-        // reshow the one that was shown least recently.
+        // reshow a random one of the 100 least recently shown profiles.
         //
-        $result = _mysql_query("SELECT * FROM profile,user WHERE profile.userid=user.id AND verification=1 ORDER BY uotd_time ASC LIMIT 1");
+        $inner = "SELECT profile.userid FROM profile,user WHERE profile.userid=user.id AND verification=1 AND uotd_time>0 ORDER BY uotd_time ASC LIMIT 100";
+        $result = $db->do_query("SELECT * from ($inner) ORDER BY RAND() LIMIT 1");
     }
 
-    if (!$result || _mysql_num_rows($result) == 0) {
+    if (!$result || $result->num_rows == 0) {
         // No valid users of the day - do something.
         echo "No screened users found\n";
         exit();
     }
-    $profile = _mysql_fetch_object($result);
-    $user = BoincUser::lookup_id($profile->userid);
+    $candidate = $result->fetch_object();
+    $result->free();
 
-    // if profile is "orphaned", delete it and try again
+    // depending on the candidates query the profile must not exist
     //
-    if (!$user) {
-        $profile->delete_aux("userid=$profile->userid");
-        select_uotd();
+    $profile = BoincProfile::lookup_userid($candidate->userid);
+    if (!$profile) {
+        echo "Could not find profile returned from candidates query.\n";
+        exit();
     }
 
-    $sql = "UPDATE profile SET uotd_time = ".time()." WHERE userid=$user->id";
-    _mysql_query($sql);
+    // "orphaned" profiles can only be detected if the candidate query doesn't join profile and user table
+    // if this happens, delete the profile and try again
+    //
+    $user = BoincUser::lookup_id($candidate->userid);
+    if (!$user) {
+        echo "Profile for user $candidate->userid is orphaned and will be deleted\n";
+        $profile->delete();
+        select_uotd($force_new);
+        exit();
+    }
+
+    $profile->uotd_time = time();
+    $profile->update("uotd_time = ".time());
 
     send_email($user,
         "You're the " . PROJECT . " user of the day!",
@@ -131,7 +153,7 @@ function select_uotd() {
         Your profile will be featured on the " . PROJECT . " website for the next 24 hours."
     );
     echo "Chose user $user->id as UOTD\n";
-    $profile->uotd_time = time();
+
     generate_uotd_gadget($profile, $user);
 }
 
@@ -143,7 +165,7 @@ function default_uotd_candidates_query(){
     $query = "SELECT * FROM profile,user WHERE profile.userid=user.id ";
     $query .= " AND verification=1 ";
     $query .= " AND expavg_credit>1 ";
-    $query .= " AND uotd_time IS NULL ";
+    $query .= " AND (uotd_time IS NULL or uotd_time=0) ";
     $query .= "ORDER BY RAND()";
     return $query;
 }
@@ -159,11 +181,12 @@ function count_uotd_candidates(){
         $query = default_uotd_candidates_query();
     }
     
-    $result = _mysql_query($query);
+    $db = BoincDb::get();
+    $result = $db->do_query($query);
     if($result) {
-        $n = _mysql_num_rows($result);
+        $n = $result->num_rows;
     }
-    _mysql_free_result($result);
+    $result->free();
     
     return $n;
 }
diff --git a/html/ops/profile_screen_form.php b/html/ops/profile_screen_form.php
index 8213d02c30..ff0cb6d50b 100644
--- a/html/ops/profile_screen_form.php
+++ b/html/ops/profile_screen_form.php
@@ -46,7 +46,7 @@ if (function_exists('profile_screen_query')) {
     $query = "select * from profile, user where profile.userid=user.id "
         ." and has_picture>0 "
         ." and verification=0 "
-        ." and uotd_time is null "
+        ." and (uotd_time is null or uotd_time=0) "
         ." and expavg_credit>1 "
         ." and (response1 <> '' or response2 <> '') "
         ." order by recommend desc limit 20"
diff --git a/html/ops/update_uotd.php b/html/ops/update_uotd.php
index aafec6e69b..611285847f 100755
--- a/html/ops/update_uotd.php
+++ b/html/ops/update_uotd.php
@@ -3,7 +3,7 @@
 <?php
 // This file is part of BOINC.
 // http://boinc.berkeley.edu
-// Copyright (C) 2008 University of California
+// Copyright (C) 2015 University of California
 //
 // BOINC is free software; you can redistribute it and/or modify it
 // under the terms of the GNU Lesser General Public License
@@ -21,7 +21,16 @@
 require_once("../inc/util_ops.inc");
 require_once("../inc/uotd.inc");
 
-db_init();
+$force_new = false;
+if ($argc > 1) {
+    if ($argv[1] == "-f" || $argv[1] == "--force") {
+        $force_new = true;
+    } else {
+        echo "Usage: ".$argv[0]." [-f|--force]\n";
+        echo "     -f | --force  Will select a new User of the day regardless if there already is one for the current day\n";
+        exit(1);
+    }
+}
 
-select_uotd();
+select_uotd($force_new);
 ?>