diff --git a/locallib.php b/locallib.php
index 8d4ff15..11b73ff 100644
--- a/locallib.php
+++ b/locallib.php
@@ -916,7 +916,7 @@ class attendance {
         global $DB, $CFG;
 
         // Fields we need from the user table.
-        $userfields = user_picture::fields('u').',u.username';
+        $userfields = user_picture::fields('u', array('username'));
 
         if (isset($this->pageparams->sort) and ($this->pageparams->sort == ATT_SORT_FIRSTNAME)) {
             $orderby = "u.firstname ASC, u.lastname ASC";
@@ -936,10 +936,10 @@ class attendance {
                 $users = get_users_by_capability($this->context, 'mod/attendance:canbelisted',
                                 $userfields.',u.id, u.firstname, u.lastname, u.email',
                                 $orderby, $startusers, $usersperpage, $groups,
-                                '', false, true);			
+                                '', false, true);
             } else {
                 $startusers = ($page - 1) * $usersperpage;
-                $users = get_enrolled_users($this->context, 'mod/attendance:canbelisted', $groupid, $userfields, $orderby, $startusers, $usersperpage);            
+                $users = get_enrolled_users($this->context, 'mod/attendance:canbelisted', $groupid, $userfields, $orderby, $startusers, $usersperpage);
             }
         } else {
             if (!empty($CFG->enablegroupmembersonly) and $this->cm->groupmembersonly) {
@@ -959,23 +959,29 @@ class attendance {
 
         // Add a flag to each user indicating whether their enrolment is active.
         if (!empty($users)) {
-            list($usql, $uparams) = $DB->get_in_or_equal(array_keys($users), SQL_PARAMS_NAMED, 'usid0');
+            list($sql, $params) = $DB->get_in_or_equal(array_keys($users), SQL_PARAMS_NAMED, 'usid0');
+
+            // CONTRIB-4868
+            $mintime = 'MIN(CASE WHEN (ue.timestart > :zerotime) THEN ue.timestart ELSE ue.timecreated END)';
+            $maxtime = 'MAX(ue.timeend)';
 
-            // CONTRIB-3549.
-            $sql = "SELECT ue.userid, ue.status, ue.timestart, ue.timeend
+            // CONTRIB-3549
+            $sql = "SELECT ue.userid, ue.status,
+                           $mintime AS mintime,
+                           $maxtime AS maxtime
                       FROM {user_enrolments} ue
                       JOIN {enrol} e ON e.id = ue.enrolid
-                     WHERE ue.userid $usql
+                     WHERE ue.userid $sql
                            AND e.status = :estatus
                            AND e.courseid = :courseid
-                  GROUP BY ue.userid, ue.status, ue.timestart, ue.timeend";
-            $params = array_merge($uparams, array('estatus'=>ENROL_INSTANCE_ENABLED, 'courseid'=>$this->course->id));
-            $enrolmentsparams = $DB->get_records_sql($sql, $params);
+                  GROUP BY ue.userid, ue.status";
+            $params += array('zerotime'=>0, 'estatus'=>ENROL_INSTANCE_ENABLED, 'courseid'=>$this->course->id);
+            $enrolments = $DB->get_records_sql($sql, $params);
 
             foreach ($users as $user) {
-                $users[$user->id]->enrolmentstatus = $enrolmentsparams[$user->id]->status;
-                $users[$user->id]->enrolmentstart = $enrolmentsparams[$user->id]->timestart;
-                $users[$user->id]->enrolmentend = $enrolmentsparams[$user->id]->timeend;
+                $users[$user->id]->enrolmentstatus = $enrolments[$user->id]->status;
+                $users[$user->id]->enrolmentstart = $enrolments[$user->id]->mintime;
+                $users[$user->id]->enrolmentend = $enrolments[$user->id]->maxtime;
             }
         }
 
@@ -987,19 +993,25 @@ class attendance {
 
         $user = $DB->get_record('user', array('id' => $userid), '*', MUST_EXIST);
 
-        $sql = "SELECT ue.userid, ue.status, ue.timestart, ue.timeend
+        // CONTRIB-4868
+        $mintime = 'MIN(CASE WHEN (ue.timestart > :zerotime) THEN ue.timestart ELSE ue.timecreated END)';
+        $maxtime = 'MAX(ue.timeend)';
+
+        $sql = "SELECT ue.userid, ue.status,
+                       $mintime AS mintime,
+                       $maxtime AS maxtime
                   FROM {user_enrolments} ue
                   JOIN {enrol} e ON e.id = ue.enrolid
                  WHERE ue.userid = :uid
                        AND e.status = :estatus
                        AND e.courseid = :courseid
-              GROUP BY ue.userid, ue.status, ue.timestart, ue.timeend";
-        $params = array('uid' => $userid, 'estatus'=>ENROL_INSTANCE_ENABLED, 'courseid'=>$this->course->id);
-        $enrolmentsparams = $DB->get_record_sql($sql, $params);
+              GROUP BY ue.userid, ue.status";
+        $params = array('zerotime'=>0, 'uid'=>$userid, 'estatus'=>ENROL_INSTANCE_ENABLED, 'courseid'=>$this->course->id);
+        $enrolments = $DB->get_record_sql($sql, $params);
 
-        $user->enrolmentstatus = $enrolmentsparams->status;
-        $user->enrolmentstart = $enrolmentsparams->timestart;
-        $user->enrolmentend = $enrolmentsparams->timeend;
+        $user->enrolmentstatus = $enrolments->status;
+        $user->enrolmentstart = $enrolments->mintime;
+        $user->enrolmentend = $enrolments->maxtime;
 
         return $user;
     }