Index: resources/sql/autopatches/20140205.cal.2.phid-col.sql
===================================================================
--- /dev/null
+++ resources/sql/autopatches/20140205.cal.2.phid-col.sql
@@ -0,0 +1,2 @@
+ALTER TABLE {$NAMESPACE}_calendar.calendar_event
+  ADD phid VARCHAR(64) NOT NULL COLLATE utf8_bin AFTER id;
Index: resources/sql/autopatches/20140205.cal.3.phid-mig.php
===================================================================
--- /dev/null
+++ resources/sql/autopatches/20140205.cal.3.phid-mig.php
@@ -0,0 +1,22 @@
+<?php
+
+$table = new PhabricatorCalendarEvent();
+$conn_w = $table->establishConnection('w');
+
+echo "Assigning PHIDs to events...\n";
+foreach (new LiskMigrationIterator($table) as $event) {
+  $id = $event->getID();
+
+  echo "Updating event {$id}...\n";
+  if ($event->getPHID()) {
+    continue;
+  }
+
+  queryfx(
+    $conn_w,
+    'UPDATE %T SET phid = %s WHERE id = %d',
+    $table->getTableName(),
+    $table->generatePHID(),
+    $id);
+}
+echo "Done.\n";
Index: resources/sql/autopatches/20140205.cal.4.phid-key.sql
===================================================================
--- /dev/null
+++ resources/sql/autopatches/20140205.cal.4.phid-key.sql
@@ -0,0 +1,2 @@
+ALTER TABLE {$NAMESPACE}_calendar.calendar_event
+  ADD UNIQUE KEY `key_phid` (phid);
Index: src/__phutil_library_map__.php
===================================================================
--- src/__phutil_library_map__.php
+++ src/__phutil_library_map__.php
@@ -1271,6 +1271,7 @@
     'PhabricatorCalendarEventViewController' => 'applications/calendar/controller/PhabricatorCalendarEventViewController.php',
     'PhabricatorCalendarHoliday' => 'applications/calendar/storage/PhabricatorCalendarHoliday.php',
     'PhabricatorCalendarHolidayTestCase' => 'applications/calendar/storage/__tests__/PhabricatorCalendarHolidayTestCase.php',
+    'PhabricatorCalendarPHIDTypeEvent' => 'applications/calendar/phid/PhabricatorCalendarPHIDTypeEvent.php',
     'PhabricatorCampfireProtocolAdapter' => 'infrastructure/daemon/bot/adapter/PhabricatorCampfireProtocolAdapter.php',
     'PhabricatorChangeParserTestCase' => 'applications/repository/worker/__tests__/PhabricatorChangeParserTestCase.php',
     'PhabricatorChangesetResponse' => 'infrastructure/diff/PhabricatorChangesetResponse.php',
@@ -3920,6 +3921,7 @@
     'PhabricatorCalendarEventViewController' => 'PhabricatorDashboardController',
     'PhabricatorCalendarHoliday' => 'PhabricatorCalendarDAO',
     'PhabricatorCalendarHolidayTestCase' => 'PhabricatorTestCase',
+    'PhabricatorCalendarPHIDTypeEvent' => 'PhabricatorPHIDType',
     'PhabricatorCampfireProtocolAdapter' => 'PhabricatorBotBaseStreamingProtocolAdapter',
     'PhabricatorChangeParserTestCase' => 'PhabricatorWorkingCopyTestCase',
     'PhabricatorChangesetResponse' => 'AphrontProxyResponse',
Index: src/applications/calendar/phid/PhabricatorCalendarPHIDTypeEvent.php
===================================================================
--- /dev/null
+++ src/applications/calendar/phid/PhabricatorCalendarPHIDTypeEvent.php
@@ -0,0 +1,41 @@
+<?php
+
+final class PhabricatorCalendarPHIDTypeEvent extends PhabricatorPHIDType {
+
+  const TYPECONST = 'CEVT';
+
+  public function getTypeConstant() {
+    return self::TYPECONST;
+  }
+
+  public function getTypeName() {
+    return pht('Event');
+  }
+
+  public function newObject() {
+    return new PhabricatorCalendarEvent();
+  }
+
+  protected function buildQueryForObjects(
+    PhabricatorObjectQuery $query,
+    array $phids) {
+
+    return id(new PhabricatorCalendarEventQuery())
+      ->withPHIDs($phids);
+  }
+
+  public function loadHandles(
+    PhabricatorHandleQuery $query,
+    array $handles,
+    array $objects) {
+
+    foreach ($handles as $phid => $handle) {
+      $event = $objects[$phid];
+
+      $id = $event->getID();
+
+      $handle->setName(pht('Event %d', $id));
+    }
+  }
+
+}
Index: src/applications/calendar/query/PhabricatorCalendarEventQuery.php
===================================================================
--- src/applications/calendar/query/PhabricatorCalendarEventQuery.php
+++ src/applications/calendar/query/PhabricatorCalendarEventQuery.php
@@ -4,6 +4,7 @@
   extends PhabricatorCursorPagedPolicyAwareQuery {
 
   private $ids;
+  private $phids;
   private $rangeBegin;
   private $rangeEnd;
   private $invitedPHIDs;
@@ -14,6 +15,11 @@
     return $this;
   }
 
+  public function withPHIDs(array $phids) {
+    $this->phids = $phids;
+    return $this;
+  }
+
   public function withDateRange($begin, $end) {
     $this->rangeBegin = $begin;
     $this->rangeEnd = $end;
@@ -55,6 +61,13 @@
         $this->ids);
     }
 
+    if ($this->phids) {
+      $where[] = qsprintf(
+        $conn_r,
+        'phid IN (%Ls)',
+        $this->phids);
+    }
+
     if ($this->rangeBegin) {
       $where[] = qsprintf(
         $conn_r,
Index: src/applications/calendar/storage/PhabricatorCalendarEvent.php
===================================================================
--- src/applications/calendar/storage/PhabricatorCalendarEvent.php
+++ src/applications/calendar/storage/PhabricatorCalendarEvent.php
@@ -34,6 +34,17 @@
     return $options[$this->status];
   }
 
+  public function getConfiguration() {
+    return array(
+      self::CONFIG_AUX_PHID => true,
+    ) + parent::getConfiguration();
+  }
+
+  public function generatePHID() {
+    return PhabricatorPHID::generateNewPHID(
+      PhabricatorCalendarPHIDTypeEvent::TYPECONST);
+  }
+
   public function getTerseSummary(PhabricatorUser $viewer) {
     $until = phabricator_date($this->dateTo, $viewer);
     if ($this->status == PhabricatorCalendarEvent::STATUS_SPORADIC) {