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
@@ -2036,6 +2036,7 @@
     'PhabricatorCalendarEventEndDateTransaction' => 'applications/calendar/xaction/PhabricatorCalendarEventEndDateTransaction.php',
     'PhabricatorCalendarEventFrequencyTransaction' => 'applications/calendar/xaction/PhabricatorCalendarEventFrequencyTransaction.php',
     'PhabricatorCalendarEventFulltextEngine' => 'applications/calendar/search/PhabricatorCalendarEventFulltextEngine.php',
+    'PhabricatorCalendarEventHostTransaction' => 'applications/calendar/xaction/PhabricatorCalendarEventHostTransaction.php',
     'PhabricatorCalendarEventIconTransaction' => 'applications/calendar/xaction/PhabricatorCalendarEventIconTransaction.php',
     'PhabricatorCalendarEventInviteTransaction' => 'applications/calendar/xaction/PhabricatorCalendarEventInviteTransaction.php',
     'PhabricatorCalendarEventInvitee' => 'applications/calendar/storage/PhabricatorCalendarEventInvitee.php',
@@ -6663,6 +6664,7 @@
     'PhabricatorCalendarEventEndDateTransaction' => 'PhabricatorCalendarEventDateTransaction',
     'PhabricatorCalendarEventFrequencyTransaction' => 'PhabricatorCalendarEventTransactionType',
     'PhabricatorCalendarEventFulltextEngine' => 'PhabricatorFulltextEngine',
+    'PhabricatorCalendarEventHostTransaction' => 'PhabricatorCalendarEventTransactionType',
     'PhabricatorCalendarEventIconTransaction' => 'PhabricatorCalendarEventTransactionType',
     'PhabricatorCalendarEventInviteTransaction' => 'PhabricatorCalendarEventTransactionType',
     'PhabricatorCalendarEventInvitee' => array(
diff --git a/src/applications/calendar/editor/PhabricatorCalendarEventEditEngine.php b/src/applications/calendar/editor/PhabricatorCalendarEventEditEngine.php
--- a/src/applications/calendar/editor/PhabricatorCalendarEventEditEngine.php
+++ b/src/applications/calendar/editor/PhabricatorCalendarEventEditEngine.php
@@ -23,8 +23,7 @@
 
   protected function newEditableObject() {
     return PhabricatorCalendarEvent::initializeNewCalendarEvent(
-      $this->getViewer(),
-      $mode = null);
+      $this->getViewer());
   }
 
   protected function newObjectQuery() {
@@ -106,6 +105,17 @@
         ->setConduitDescription(pht('Cancel or restore the event.'))
         ->setConduitTypeDescription(pht('True to cancel the event.'))
         ->setValue($object->getIsCancelled()),
+      id(new PhabricatorUsersEditField())
+        ->setKey('hostPHID')
+        ->setAliases(array('host'))
+        ->setLabel(pht('Host'))
+        ->setDescription(pht('Host of the event.'))
+        ->setTransactionType(
+          PhabricatorCalendarEventHostTransaction::TRANSACTIONTYPE)
+        ->setIsConduitOnly($this->getIsCreate())
+        ->setConduitDescription(pht('Change the host of the event.'))
+        ->setConduitTypeDescription(pht('New event host.'))
+        ->setSingleValue($object->getHostPHID()),
       id(new PhabricatorDatasourceEditField())
         ->setKey('inviteePHIDs')
         ->setAliases(array('invite', 'invitee', 'invitees', 'inviteePHID'))
@@ -141,7 +151,7 @@
         ->setDescription(pht('Recurring event frequency.'))
         ->setConduitDescription(pht('Change the event frequency.'))
         ->setConduitTypeDescription(pht('New event frequency.'))
-        ->setValue($object->getFrequencyUnit());
+        ->setValue($object->getFrequencyRule());
     }
 
     if ($this->getIsCreate() || $object->getIsRecurring()) {
diff --git a/src/applications/calendar/storage/PhabricatorCalendarEvent.php b/src/applications/calendar/storage/PhabricatorCalendarEvent.php
--- a/src/applications/calendar/storage/PhabricatorCalendarEvent.php
+++ b/src/applications/calendar/storage/PhabricatorCalendarEvent.php
@@ -39,8 +39,6 @@
 
   protected $spacePHID;
 
-  const DEFAULT_ICON = 'fa-calendar';
-
   private $parentEvent = self::ATTACHABLE;
   private $invitees = self::ATTACHABLE;
 
@@ -53,24 +51,13 @@
   const FREQUENCY_MONTHLY = 'monthly';
   const FREQUENCY_YEARLY = 'yearly';
 
-  public static function initializeNewCalendarEvent(
-    PhabricatorUser $actor,
-    $mode) {
+  public static function initializeNewCalendarEvent(PhabricatorUser $actor) {
     $app = id(new PhabricatorApplicationQuery())
       ->setViewer($actor)
       ->withClasses(array('PhabricatorCalendarApplication'))
       ->executeOne();
 
-    $view_policy = null;
-    $is_recurring = 0;
-
-    if ($mode == 'public') {
-      $view_policy = PhabricatorPolicies::getMostOpenPolicy();
-    }
-
-    if ($mode == 'recurring') {
-      $is_recurring = true;
-    }
+    $view_policy = PhabricatorPolicies::getMostOpenPolicy();
 
     $start = new DateTime('@'.PhabricatorTime::getNow());
     $start->setTimeZone($actor->getTimeZone());
@@ -82,13 +69,19 @@
     $epoch_min = $start->format('U');
     $epoch_max = $end->format('U');
 
+    $default_icon = 'fa-calendar';
+
     return id(new PhabricatorCalendarEvent())
       ->setHostPHID($actor->getPHID())
       ->setIsCancelled(0)
       ->setIsAllDay(0)
       ->setIsStub(0)
-      ->setIsRecurring($is_recurring)
-      ->setIcon(self::DEFAULT_ICON)
+      ->setIsRecurring(0)
+      ->setRecurrenceFrequency(
+        array(
+          'rule' => self::FREQUENCY_WEEKLY,
+        ))
+      ->setIcon($default_icon)
       ->setViewPolicy($view_policy)
       ->setEditPolicy($actor->getPHID())
       ->setSpacePHID($actor->getDefaultSpacePHID())
@@ -396,8 +389,12 @@
     return $this;
   }
 
+  public function getFrequencyRule() {
+    return idx($this->recurrenceFrequency, 'rule');
+  }
+
   public function getFrequencyUnit() {
-    $frequency = idx($this->recurrenceFrequency, 'rule');
+    $frequency = $this->getFrequencyRule();
 
     switch ($frequency) {
       case 'daily':
diff --git a/src/applications/calendar/xaction/PhabricatorCalendarEventFrequencyTransaction.php b/src/applications/calendar/xaction/PhabricatorCalendarEventFrequencyTransaction.php
--- a/src/applications/calendar/xaction/PhabricatorCalendarEventFrequencyTransaction.php
+++ b/src/applications/calendar/xaction/PhabricatorCalendarEventFrequencyTransaction.php
@@ -6,7 +6,7 @@
   const TRANSACTIONTYPE = 'calendar.frequency';
 
   public function generateOldValue($object) {
-    return $object->getFrequencyUnit();
+    return $object->getFrequencyRule();
   }
 
   public function applyInternalEffects($object, $value) {
@@ -17,7 +17,7 @@
   }
 
   public function getTitle() {
-    $frequency = $this->getFrequencyUnit($this->getNewValue());
+    $frequency = $this->getFrequencyRule($this->getNewValue());
     switch ($frequency) {
       case PhabricatorCalendarEvent::FREQUENCY_DAILY:
         return pht(
@@ -39,7 +39,7 @@
   }
 
   public function getTitleForFeed() {
-    $frequency = $this->getFrequencyUnit($this->getNewValue());
+    $frequency = $this->getFrequencyRule($this->getNewValue());
     switch ($frequency) {
       case PhabricatorCalendarEvent::FREQUENCY_DAILY:
         return pht(
@@ -64,7 +64,7 @@
     }
   }
 
-  private function getFrequencyUnit($value) {
+  private function getFrequencyRule($value) {
     if (is_array($value)) {
       $value = idx($value, 'rule');
     } else {
diff --git a/src/applications/calendar/xaction/PhabricatorCalendarEventHostTransaction.php b/src/applications/calendar/xaction/PhabricatorCalendarEventHostTransaction.php
new file mode 100644
--- /dev/null
+++ b/src/applications/calendar/xaction/PhabricatorCalendarEventHostTransaction.php
@@ -0,0 +1,59 @@
+<?php
+
+final class PhabricatorCalendarEventHostTransaction
+  extends PhabricatorCalendarEventTransactionType {
+
+  const TRANSACTIONTYPE = 'calendar.host';
+
+  public function generateOldValue($object) {
+    return $object->getHostPHID();
+  }
+
+  public function applyInternalEffects($object, $value) {
+    $object->setHostPHID($value);
+  }
+
+  public function getTitle() {
+    return pht(
+      '%s changed the host of this event from %s to %s.',
+      $this->renderAuthor(),
+      $this->renderOldHandle(),
+      $this->renderNewHandle());
+  }
+
+  public function getTitleForFeed() {
+    return pht(
+      '%s changed the host of %s from %s to %s.',
+      $this->renderAuthor(),
+      $this->renderObject(),
+      $this->renderOldHandle(),
+      $this->renderNewHandle());
+  }
+
+  public function validateTransactions($object, array $xactions) {
+    $errors = array();
+
+    foreach ($xactions as $xaction) {
+      $host_phid = $xaction->getNewValue();
+      if (!$host_phid) {
+        $errors[] = $this->newRequiredError(
+          pht('Event host is required.'));
+        continue;
+      }
+
+      $user = id(new PhabricatorPeopleQuery())
+        ->setViewer($this->getActor())
+        ->withPHIDs(array($host_phid))
+        ->executeOne();
+      if (!$user) {
+        $errors[] = $this->newInvalidError(
+          pht(
+            'Host PHID "%s" is not a valid user PHID.',
+            $host_phid));
+      }
+    }
+
+    return $errors;
+  }
+
+}
diff --git a/src/applications/transactions/storage/PhabricatorModularTransactionType.php b/src/applications/transactions/storage/PhabricatorModularTransactionType.php
--- a/src/applications/transactions/storage/PhabricatorModularTransactionType.php
+++ b/src/applications/transactions/storage/PhabricatorModularTransactionType.php
@@ -148,6 +148,14 @@
     return $display;
   }
 
+  final protected function renderOldHandle() {
+    return $this->renderHandle($this->getOldValue());
+  }
+
+  final protected function renderNewHandle() {
+    return $this->renderHandle($this->getNewValue());
+  }
+
   final protected function renderHandleList(array $phids) {
     $viewer = $this->getViewer();
     $display = $viewer->renderHandleList($phids)