diff --git a/src/applications/calendar/controller/PhabricatorCalendarEventEditController.php b/src/applications/calendar/controller/PhabricatorCalendarEventEditController.php
--- a/src/applications/calendar/controller/PhabricatorCalendarEventEditController.php
+++ b/src/applications/calendar/controller/PhabricatorCalendarEventEditController.php
@@ -324,7 +324,7 @@
         ->setID($recurrence_end_date_id)
         ->setIsTimeDisabled(true)
         ->setAllowNull(true)
-        ->setIsDisabled(!$is_recurring);
+        ->setIsDisabled($recurrence_end_date_value->isDisabled());
 
       $recurrence_frequency_select = id(new AphrontFormSelectControl())
         ->setName('frequency')
diff --git a/src/applications/calendar/editor/PhabricatorCalendarEventEditor.php b/src/applications/calendar/editor/PhabricatorCalendarEventEditor.php
--- a/src/applications/calendar/editor/PhabricatorCalendarEventEditor.php
+++ b/src/applications/calendar/editor/PhabricatorCalendarEventEditor.php
@@ -265,10 +265,20 @@
   protected function validateAllTransactions(
     PhabricatorLiskDAO $object,
     array $xactions) {
-    $start_date_xaction = PhabricatorCalendarEventTransaction::TYPE_START_DATE;
-    $end_date_xaction = PhabricatorCalendarEventTransaction::TYPE_END_DATE;
+    $start_date_xaction =
+      PhabricatorCalendarEventTransaction::TYPE_START_DATE;
+    $end_date_xaction =
+      PhabricatorCalendarEventTransaction::TYPE_END_DATE;
+    $is_recurrence_xaction =
+      PhabricatorCalendarEventTransaction::TYPE_RECURRING;
+    $recurrence_end_xaction =
+      PhabricatorCalendarEventTransaction::TYPE_RECURRENCE_END_DATE;
+
     $start_date = $object->getDateFrom();
     $end_date = $object->getDateTo();
+    $recurrence_end = $object->getRecurrenceEndDate();
+    $is_recurring = $object->getIsRecurring();
+
     $errors = array();
 
     foreach ($xactions as $xaction) {
@@ -276,6 +286,10 @@
         $start_date = $xaction->getNewValue()->getEpoch();
       } else if ($xaction->getTransactionType() == $end_date_xaction) {
         $end_date = $xaction->getNewValue()->getEpoch();
+      } else if ($xaction->getTransactionType() == $recurrence_end_xaction) {
+        $recurrence_end = $xaction->getNewValue();
+      } else if ($xaction->getTransactionType() == $is_recurrence_xaction) {
+        $is_recurring = $xaction->getNewValue();
       }
     }
     if ($start_date > $end_date) {
@@ -287,6 +301,16 @@
         null);
     }
 
+    if ($recurrence_end && !$is_recurring) {
+      $type =
+        PhabricatorCalendarEventTransaction::TYPE_RECURRENCE_END_DATE;
+      $errors[] = new PhabricatorApplicationTransactionValidationError(
+        $type,
+        pht('Invalid'),
+        pht('Event must be recurring to have a recurrence end date.').
+        null);
+    }
+
     return $errors;
   }
 
diff --git a/webroot/rsrc/js/application/calendar/behavior-recurring-edit.js b/webroot/rsrc/js/application/calendar/behavior-recurring-edit.js
--- a/webroot/rsrc/js/application/calendar/behavior-recurring-edit.js
+++ b/webroot/rsrc/js/application/calendar/behavior-recurring-edit.js
@@ -5,17 +5,37 @@
 
 JX.behavior('recurring-edit', function(config) {
   var checkbox = JX.$(config.isRecurring);
+  var frequency = JX.$(config.frequency);
+  var end_date = JX.$(config.recurrenceEndDate);
 
-  JX.DOM.listen(checkbox, 'change', null, function() {
-    var frequency = JX.$(config.frequency);
-    var end_date = JX.$(config.recurrenceEndDate);
+  var end_date_checkbox = JX.DOM.find(end_date, 'input', 'calendar-enable');
 
-    frequency.disabled = checkbox.checked ? false : true;
-    end_date.disabled = checkbox.checked ? false : true;
+  JX.DOM.listen(checkbox, 'change', null, function() {
+    if (checkbox.checked) {
+      enableRecurring();
+    } else {
+      disableRecurring();
+    }
+  });
 
-    if (end_date.disabled) {
-      JX.DOM.alterClass(end_date, 'datepicker-disabled', !checkbox.checked);
+  JX.DOM.listen(end_date, 'change', null, function() {
+    if (end_date_checkbox.checked) {
+      enableRecurring();
     }
   });
 
+  function enableRecurring() {
+    checkbox.checked = true;
+    frequency.disabled = false;
+    end_date.disabled = false;
+  }
+
+  function disableRecurring() {
+    checkbox.checked = false;
+    frequency.disabled = true;
+    end_date.disabled = true;
+    end_date_checkbox.checked = false;
+
+    JX.DOM.alterClass(end_date, 'datepicker-disabled', true);
+  }
 });