workaround by Dan for bug #3130, fixed some warnings

calendar/event.php

@@ -485,6 +485,9 @@
 
             if($eventtype == 'select') {
                 $courseid = optional_param('courseid', $SESSION->cal_course_referer, PARAM_INT);
+                if ($courseid == 0) { // workaround by Dan for bug #3130
+                    $courseid = SITEID;
+                }
                 if (!$course = get_record('course', 'id', $courseid)) {
                     error('Incorrect course ID');
                 }

calendar/event_new.html

@@ -29,9 +29,9 @@
       <?php print_string('eventdate', 'calendar'); ?>:
     </td>
     <td>
-      <?php print_date_selector('startday', 'startmon', 'startyr', $form->timestart);?>
+      <?php print_date_selector('startday', 'startmon', 'startyr', (int)$form->timestart);?>
       <?php print_string('eventtime', 'calendar');?>
-      <?php print_time_selector('starthr', 'startmin', $form->timestart) ?>
+      <?php print_time_selector('starthr', 'startmin', (int)$form->timestart) ?>
       <?php if (isset($err['timestart'])) formerr($err['timestart']); ?>
     </td>
   </tr>