diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -6633,7 +6633,7 @@
     'PhabricatorCalendarEventCancelController' => 'PhabricatorCalendarController',
     'PhabricatorCalendarEventDragController' => 'PhabricatorCalendarController',
     'PhabricatorCalendarEventEditController' => 'PhabricatorCalendarController',
-    'PhabricatorCalendarEventEditProController' => 'ManiphestController',
+    'PhabricatorCalendarEventEditProController' => 'PhabricatorCalendarController',
     'PhabricatorCalendarEventEditor' => 'PhabricatorApplicationTransactionEditor',
     'PhabricatorCalendarEventEmailCommand' => 'MetaMTAEmailTransactionCommand',
     'PhabricatorCalendarEventFulltextEngine' => 'PhabricatorFulltextEngine',
diff --git a/src/aphront/httpparametertype/AphrontEpochHTTPParameterType.php b/src/aphront/httpparametertype/AphrontEpochHTTPParameterType.php
--- a/src/aphront/httpparametertype/AphrontEpochHTTPParameterType.php
+++ b/src/aphront/httpparametertype/AphrontEpochHTTPParameterType.php
@@ -3,13 +3,30 @@
 final class AphrontEpochHTTPParameterType
   extends AphrontHTTPParameterType {
 
+  private $allowNull;
+
+  public function setAllowNull($allow_null) {
+    $this->allowNull = $allow_null;
+    return $this;
+  }
+
+  public function getAllowNull() {
+    return $this->allowNull;
+  }
+
   protected function getParameterExists(AphrontRequest $request, $key) {
     return $request->getExists($key) ||
            $request->getExists($key.'_d');
   }
 
   protected function getParameterValue(AphrontRequest $request, $key) {
-    return AphrontFormDateControlValue::newFromRequest($request, $key);
+    $value = AphrontFormDateControlValue::newFromRequest($request, $key);
+
+    if ($this->getAllowNull()) {
+      $value->setOptional(true);
+    }
+
+    return $value;
   }
 
   protected function getParameterTypeName() {
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
@@ -185,7 +185,7 @@
           $xactions[] = id(new PhabricatorCalendarEventTransaction())
             ->setTransactionType(
               PhabricatorCalendarEventTransaction::TYPE_RECURRENCE_END_DATE)
-            ->setNewValue($recurrence_end_date_value->getEpoch());
+            ->setNewValue($recurrence_end_date_value);
         }
       }
 
@@ -203,12 +203,12 @@
         $xactions[] = id(new PhabricatorCalendarEventTransaction())
           ->setTransactionType(
             PhabricatorCalendarEventTransaction::TYPE_START_DATE)
-          ->setNewValue($start_value->getEpoch());
+          ->setNewValue($start_value);
 
         $xactions[] = id(new PhabricatorCalendarEventTransaction())
           ->setTransactionType(
             PhabricatorCalendarEventTransaction::TYPE_END_DATE)
-          ->setNewValue($end_value->getEpoch());
+          ->setNewValue($end_value);
       }
 
 
diff --git a/src/applications/calendar/controller/PhabricatorCalendarEventEditProController.php b/src/applications/calendar/controller/PhabricatorCalendarEventEditProController.php
--- a/src/applications/calendar/controller/PhabricatorCalendarEventEditProController.php
+++ b/src/applications/calendar/controller/PhabricatorCalendarEventEditProController.php
@@ -1,7 +1,7 @@
 <?php
 
 final class PhabricatorCalendarEventEditProController
-  extends ManiphestController {
+  extends PhabricatorCalendarController {
 
   public function handleRequest(AphrontRequest $request) {
     return id(new PhabricatorCalendarEditEngine())
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
@@ -85,9 +85,9 @@
     PhabricatorApplicationTransaction $xaction) {
     switch ($xaction->getTransactionType()) {
       case PhabricatorCalendarEventTransaction::TYPE_RECURRING:
-        return $object->getIsRecurring();
+        return (int)$object->getIsRecurring();
       case PhabricatorCalendarEventTransaction::TYPE_FREQUENCY:
-        return $object->getRecurrenceFrequency();
+        return $object->getFrequencyUnit();
       case PhabricatorCalendarEventTransaction::TYPE_RECURRENCE_END_DATE:
         return $object->getRecurrenceEndDate();
       case PhabricatorCalendarEventTransaction::TYPE_NAME:
@@ -120,7 +120,6 @@
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
     switch ($xaction->getTransactionType()) {
-      case PhabricatorCalendarEventTransaction::TYPE_RECURRING:
       case PhabricatorCalendarEventTransaction::TYPE_FREQUENCY:
       case PhabricatorCalendarEventTransaction::TYPE_NAME:
       case PhabricatorCalendarEventTransaction::TYPE_DESCRIPTION:
@@ -132,11 +131,12 @@
       case PhabricatorCalendarEventTransaction::TYPE_DECLINE:
         return PhabricatorCalendarEventInvitee::STATUS_DECLINED;
       case PhabricatorCalendarEventTransaction::TYPE_ALL_DAY:
+      case PhabricatorCalendarEventTransaction::TYPE_RECURRING:
         return (int)$xaction->getNewValue();
       case PhabricatorCalendarEventTransaction::TYPE_RECURRENCE_END_DATE:
       case PhabricatorCalendarEventTransaction::TYPE_START_DATE:
       case PhabricatorCalendarEventTransaction::TYPE_END_DATE:
-        return $xaction->getNewValue();
+        return $xaction->getNewValue()->getEpoch();
       case PhabricatorCalendarEventTransaction::TYPE_INVITE:
         $status_invited = PhabricatorCalendarEventInvitee::STATUS_INVITED;
         $status_uninvited = PhabricatorCalendarEventInvitee::STATUS_UNINVITED;
@@ -187,9 +187,12 @@
 
     switch ($xaction->getTransactionType()) {
       case PhabricatorCalendarEventTransaction::TYPE_RECURRING:
-        return $object->setIsRecurring($xaction->getNewValue());
+        return $object->setIsRecurring((int)$xaction->getNewValue());
       case PhabricatorCalendarEventTransaction::TYPE_FREQUENCY:
-        return $object->setRecurrenceFrequency($xaction->getNewValue());
+        return $object->setRecurrenceFrequency(
+          array(
+            'rule' => $xaction->getNewValue(),
+          ));
       case PhabricatorCalendarEventTransaction::TYPE_NAME:
         $object->setName($xaction->getNewValue());
         return;
@@ -370,11 +373,11 @@
 
     foreach ($xactions as $xaction) {
       if ($xaction->getTransactionType() == $start_date_xaction) {
-        $start_date = $xaction->getNewValue();
+        $start_date = $xaction->getNewValue()->getEpoch();
       } else if ($xaction->getTransactionType() == $end_date_xaction) {
-        $end_date = $xaction->getNewValue();
+        $end_date = $xaction->getNewValue()->getEpoch();
       } else if ($xaction->getTransactionType() == $recurrence_end_xaction) {
-        $recurrence_end = $xaction->getNewValue();
+        $recurrence_end = $xaction->getNewValue()->getEpoch();
       } else if ($xaction->getTransactionType() == $is_recurrence_xaction) {
         $is_recurring = $xaction->getNewValue();
       }
diff --git a/src/applications/calendar/storage/PhabricatorCalendarEventTransaction.php b/src/applications/calendar/storage/PhabricatorCalendarEventTransaction.php
--- a/src/applications/calendar/storage/PhabricatorCalendarEventTransaction.php
+++ b/src/applications/calendar/storage/PhabricatorCalendarEventTransaction.php
@@ -265,8 +265,13 @@
           $this->renderHandleLink($author_phid));
         return $text;
       case self::TYPE_FREQUENCY:
+        $rule = $new;
+        if (is_array($rule)) {
+          $rule = idx($rule, 'rule');
+        }
+
         $text = '';
-        switch ($new['rule']) {
+        switch ($rule) {
           case PhabricatorCalendarEvent::FREQUENCY_DAILY:
             $text = pht('%s set this event to repeat daily.',
               $this->renderHandleLink($author_phid));
@@ -487,8 +492,13 @@
           $this->renderHandleLink($object_phid));
         return $text;
       case self::TYPE_FREQUENCY:
+        $rule = $new;
+        if (is_array($rule)) {
+          $rule = idx($rule, 'rule');
+        }
+
         $text = '';
-        switch ($new['rule']) {
+        switch ($rule) {
           case PhabricatorCalendarEvent::FREQUENCY_DAILY:
             $text = pht('%s set %s to repeat daily.',
               $this->renderHandleLink($author_phid),
diff --git a/src/applications/transactions/editfield/PhabricatorEpochEditField.php b/src/applications/transactions/editfield/PhabricatorEpochEditField.php
--- a/src/applications/transactions/editfield/PhabricatorEpochEditField.php
+++ b/src/applications/transactions/editfield/PhabricatorEpochEditField.php
@@ -21,7 +21,8 @@
   }
 
   protected function newHTTPParameterType() {
-    return new AphrontEpochHTTPParameterType();
+    return id(new AphrontEpochHTTPParameterType())
+      ->setAllowNull($this->getAllowNull());
   }
 
   protected function newConduitParameterType() {