diff --git a/bin/calendar b/bin/calendar
new file mode 120000
index 0000000000..33929a5ba1
--- /dev/null
+++ b/bin/calendar
@@ -0,0 +1 @@
+../scripts/setup/manage_calendar.php
\ No newline at end of file
diff --git a/resources/sql/autopatches/20161031.calendar.02.notifylog.sql b/resources/sql/autopatches/20161031.calendar.02.notifylog.sql
new file mode 100644
index 0000000000..0c6b1b6a80
--- /dev/null
+++ b/resources/sql/autopatches/20161031.calendar.02.notifylog.sql
@@ -0,0 +1,8 @@
+CREATE TABLE {$NAMESPACE}_calendar.calendar_notification (
+  id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
+  eventPHID VARBINARY(64) NOT NULL,
+  utcInitialEpoch INT UNSIGNED NOT NULL,
+  targetPHID VARBINARY(64) NOT NULL,
+  didNotifyEpoch INT UNSIGNED NOT NULL,
+  UNIQUE KEY `key_notify` (eventPHID, utcInitialEpoch, targetPHID)
+) ENGINE=InnoDB, COLLATE {$COLLATE_TEXT};
diff --git a/scripts/setup/manage_calendar.php b/scripts/setup/manage_calendar.php
new file mode 100755
index 0000000000..135c42ded1
--- /dev/null
+++ b/scripts/setup/manage_calendar.php
@@ -0,0 +1,21 @@
+#!/usr/bin/env php
+<?php
+
+$root = dirname(dirname(dirname(__FILE__)));
+require_once $root.'/scripts/__init_script__.php';
+
+$args = new PhutilArgumentParser($argv);
+$args->setTagline(pht('manage Calendar'));
+$args->setSynopsis(<<<EOSYNOPSIS
+**calendar** __command__ [__options__]
+    Manage Calendar.
+
+EOSYNOPSIS
+  );
+$args->parseStandardArguments();
+
+$workflows = id(new PhutilClassMapQuery())
+  ->setAncestorClass('PhabricatorCalendarManagementWorkflow')
+  ->execute();
+$workflows[] = new PhutilHelpArgumentWorkflow();
+$args->parseWorkflows($workflows);
diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
index a7d250eba3..a9cf5ef81d 100644
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -2153,6 +2153,10 @@ phutil_register_library_map(array(
     'PhabricatorCalendarImportTriggerLogType' => 'applications/calendar/importlog/PhabricatorCalendarImportTriggerLogType.php',
     'PhabricatorCalendarImportUpdateLogType' => 'applications/calendar/importlog/PhabricatorCalendarImportUpdateLogType.php',
     'PhabricatorCalendarImportViewController' => 'applications/calendar/controller/PhabricatorCalendarImportViewController.php',
+    'PhabricatorCalendarManagementNotifyWorkflow' => 'applications/calendar/management/PhabricatorCalendarManagementNotifyWorkflow.php',
+    'PhabricatorCalendarManagementWorkflow' => 'applications/calendar/management/PhabricatorCalendarManagementWorkflow.php',
+    'PhabricatorCalendarNotification' => 'applications/calendar/storage/PhabricatorCalendarNotification.php',
+    'PhabricatorCalendarNotificationEngine' => 'applications/calendar/notifications/PhabricatorCalendarNotificationEngine.php',
     'PhabricatorCalendarRemarkupRule' => 'applications/calendar/remarkup/PhabricatorCalendarRemarkupRule.php',
     'PhabricatorCalendarReplyHandler' => 'applications/calendar/mail/PhabricatorCalendarReplyHandler.php',
     'PhabricatorCalendarSchemaSpec' => 'applications/calendar/storage/PhabricatorCalendarSchemaSpec.php',
@@ -7014,6 +7018,10 @@ phutil_register_library_map(array(
     'PhabricatorCalendarImportTriggerLogType' => 'PhabricatorCalendarImportLogType',
     'PhabricatorCalendarImportUpdateLogType' => 'PhabricatorCalendarImportLogType',
     'PhabricatorCalendarImportViewController' => 'PhabricatorCalendarController',
+    'PhabricatorCalendarManagementNotifyWorkflow' => 'PhabricatorCalendarManagementWorkflow',
+    'PhabricatorCalendarManagementWorkflow' => 'PhabricatorManagementWorkflow',
+    'PhabricatorCalendarNotification' => 'PhabricatorCalendarDAO',
+    'PhabricatorCalendarNotificationEngine' => 'Phobject',
     'PhabricatorCalendarRemarkupRule' => 'PhabricatorObjectRemarkupRule',
     'PhabricatorCalendarReplyHandler' => 'PhabricatorApplicationTransactionReplyHandler',
     'PhabricatorCalendarSchemaSpec' => 'PhabricatorConfigSchemaSpec',
diff --git a/src/applications/calendar/management/PhabricatorCalendarManagementNotifyWorkflow.php b/src/applications/calendar/management/PhabricatorCalendarManagementNotifyWorkflow.php
new file mode 100644
index 0000000000..1c0c9894a9
--- /dev/null
+++ b/src/applications/calendar/management/PhabricatorCalendarManagementNotifyWorkflow.php
@@ -0,0 +1,25 @@
+<?php
+
+final class PhabricatorCalendarManagementNotifyWorkflow
+  extends PhabricatorCalendarManagementWorkflow {
+
+  protected function didConstruct() {
+    $this
+      ->setName('notify')
+      ->setExamples('**notify** [options]')
+      ->setSynopsis(
+        pht(
+          'Test and debug notifications about upcoming events.'))
+      ->setArguments(array());
+  }
+
+  public function execute(PhutilArgumentParser $args) {
+    $viewer = $this->getViewer();
+
+    $engine = new PhabricatorCalendarNotificationEngine();
+    $engine->publishNotifications();
+
+    return 0;
+  }
+
+}
diff --git a/src/applications/calendar/management/PhabricatorCalendarManagementWorkflow.php b/src/applications/calendar/management/PhabricatorCalendarManagementWorkflow.php
new file mode 100644
index 0000000000..613a0bab64
--- /dev/null
+++ b/src/applications/calendar/management/PhabricatorCalendarManagementWorkflow.php
@@ -0,0 +1,4 @@
+<?php
+
+abstract class PhabricatorCalendarManagementWorkflow
+  extends PhabricatorManagementWorkflow {}
diff --git a/src/applications/calendar/notifications/PhabricatorCalendarNotificationEngine.php b/src/applications/calendar/notifications/PhabricatorCalendarNotificationEngine.php
new file mode 100644
index 0000000000..2051ef55d2
--- /dev/null
+++ b/src/applications/calendar/notifications/PhabricatorCalendarNotificationEngine.php
@@ -0,0 +1,200 @@
+<?php
+
+final class PhabricatorCalendarNotificationEngine
+  extends Phobject {
+
+  private $cursor;
+
+  public function getCursor() {
+    if (!$this->cursor) {
+      $now = PhabricatorTime::getNow();
+      $this->cursor = $now - phutil_units('5 minutes in seconds');
+    }
+
+    return $this->cursor;
+  }
+
+  public function publishNotifications() {
+    $cursor = $this->getCursor();
+
+    $window_min = $cursor - phutil_units('16 hours in seconds');
+    $window_max = $cursor + phutil_units('16 hours in seconds');
+
+    $viewer = PhabricatorUser::getOmnipotentUser();
+
+    $events = id(new PhabricatorCalendarEventQuery())
+      ->setViewer($viewer)
+      ->withDateRange($window_min, $window_max)
+      ->withIsCancelled(false)
+      ->withIsImported(false)
+      ->setGenerateGhosts(true)
+      ->execute();
+    if (!$events) {
+      // No events are starting soon in any timezone, so there is nothing
+      // left to be done.
+      return;
+    }
+
+    $attendee_map = array();
+    foreach ($events as $key => $event) {
+      $notifiable_phids = array();
+      foreach ($event->getInvitees() as $invitee) {
+        if (!$invitee->isAttending()) {
+          continue;
+        }
+        $notifiable_phids[] = $invitee->getInviteePHID();
+      }
+      if (!$notifiable_phids) {
+        unset($events[$key]);
+      }
+      $attendee_map[$key] = array_fuse($notifiable_phids);
+    }
+    if (!$attendee_map) {
+      // None of the events have any notifiable attendees, so there is no
+      // one to notify of anything.
+      return;
+    }
+
+    $all_attendees = array();
+    foreach ($attendee_map as $key => $attendee_phids) {
+      foreach ($attendee_phids as $attendee_phid) {
+        $all_attendees[$attendee_phid] = $attendee_phid;
+      }
+    }
+
+    $user_map = id(new PhabricatorPeopleQuery())
+      ->setViewer($viewer)
+      ->withPHIDs($all_attendees)
+      ->withIsDisabled(false)
+      ->needUserSettings(true)
+      ->execute();
+    $user_map = mpull($user_map, null, 'getPHID');
+    if (!$user_map) {
+      // None of the attendees are valid users: they're all imported users
+      // or projects or invalid or some other kind of unnotifiable entity.
+      return;
+    }
+
+    $all_event_phids = array();
+    foreach ($events as $key => $event) {
+      foreach ($event->getNotificationPHIDs() as $phid) {
+        $all_event_phids[$phid] = $phid;
+      }
+    }
+
+    $table = new PhabricatorCalendarNotification();
+    $conn = $table->establishConnection('w');
+
+    $rows = queryfx_all(
+      $conn,
+      'SELECT * FROM %T WHERE eventPHID IN (%Ls) AND targetPHID IN (%Ls)',
+      $table->getTableName(),
+      $all_event_phids,
+      $all_attendees);
+    $sent_map = array();
+    foreach ($rows as $row) {
+      $event_phid = $row['eventPHID'];
+      $target_phid = $row['targetPHID'];
+      $initial_epoch = $row['utcInitialEpoch'];
+      $sent_map[$event_phid][$target_phid][$initial_epoch] = $row;
+    }
+
+    $notify_min = $cursor;
+    $notify_max = $cursor + phutil_units('15 minutes in seconds');
+    $notify_map = array();
+    foreach ($events as $key => $event) {
+      $initial_epoch = $event->getUTCInitialEpoch();
+      $event_phids = $event->getNotificationPHIDs();
+
+      // Select attendees who actually exist, and who we have not sent any
+      // notifications to yet.
+      $attendee_phids = $attendee_map[$key];
+      $users = array_select_keys($user_map, $attendee_phids);
+      foreach ($users as $user_phid => $user) {
+        foreach ($event_phids as $event_phid) {
+          if (isset($sent_map[$event_phid][$user_phid][$initial_epoch])) {
+            unset($users[$user_phid]);
+            continue 2;
+          }
+        }
+      }
+
+      if (!$users) {
+        continue;
+      }
+
+      // Discard attendees for whom the event start time isn't soon. Events
+      // may start at different times for different users, so we need to
+      // check every user's start time.
+      foreach ($users as $user_phid => $user) {
+        $user_datetime = $event->newStartDateTime()
+          ->setViewerTimezone($user->getTimezoneIdentifier());
+
+        $user_epoch = $user_datetime->getEpoch();
+        if ($user_epoch < $notify_min || $user_epoch > $notify_max) {
+          unset($users[$user_phid]);
+          continue;
+        }
+
+        $notify_map[$user_phid][] = array(
+          'event' => $event,
+          'datetime' => $user_datetime,
+          'epoch' => $user_epoch,
+        );
+      }
+    }
+
+    $mail_list = array();
+    $mark_list = array();
+    $now = PhabricatorTime::getNow();
+    foreach ($notify_map as $user_phid => $events) {
+      $user = $user_map[$user_phid];
+      $events = isort($events, 'epoch');
+
+      // TODO: This is just a proof-of-concept that gets dumped to the console;
+      // it will be replaced with a nice fancy email and notification.
+
+      $body = array();
+      $body[] = pht('%s, these events start soon:', $user->getUsername());
+      $body[] = null;
+      foreach ($events as $spec) {
+        $event = $spec['event'];
+        $body[] = $event->getName();
+      }
+      $body = implode("\n", $body);
+
+      $mail_list[] = $body;
+
+      foreach ($events as $spec) {
+        $event = $spec['event'];
+        foreach ($event->getNotificationPHIDs() as $phid) {
+          $mark_list[] = qsprintf(
+            $conn,
+            '(%s, %s, %d, %d)',
+            $phid,
+            $user_phid,
+            $event->getUTCInitialEpoch(),
+            $now);
+        }
+      }
+    }
+
+    // Mark all the notifications we're about to send as delivered so we
+    // do not double-notify.
+    foreach (PhabricatorLiskDAO::chunkSQL($mark_list) as $chunk) {
+      queryfx(
+        $conn,
+        'INSERT IGNORE INTO %T
+          (eventPHID, targetPHID, utcInitialEpoch, didNotifyEpoch)
+          VALUES %Q',
+        $table->getTableName(),
+        $chunk);
+    }
+
+    foreach ($mail_list as $mail) {
+      echo $mail;
+      echo "\n\n";
+    }
+  }
+
+}
diff --git a/src/applications/calendar/query/PhabricatorCalendarEventQuery.php b/src/applications/calendar/query/PhabricatorCalendarEventQuery.php
index a6ac2e4ffc..3980c0635d 100644
--- a/src/applications/calendar/query/PhabricatorCalendarEventQuery.php
+++ b/src/applications/calendar/query/PhabricatorCalendarEventQuery.php
@@ -19,6 +19,7 @@ final class PhabricatorCalendarEventQuery
   private $importUIDs;
   private $utcInitialEpochMin;
   private $utcInitialEpochMax;
+  private $isImported;
 
   private $generateGhosts = false;
 
@@ -103,6 +104,11 @@ final class PhabricatorCalendarEventQuery
     return $this;
   }
 
+  public function withIsImported($is_imported) {
+    $this->isImported = $is_imported;
+    return $this;
+  }
+
   protected function getDefaultOrderVector() {
     return array('start', 'id');
   }
@@ -472,6 +478,18 @@ final class PhabricatorCalendarEventQuery
         $this->importUIDs);
     }
 
+    if ($this->isImported !== null) {
+      if ($this->isImported) {
+        $where[] = qsprintf(
+          $conn,
+          'event.importSourcePHID IS NOT NULL');
+      } else {
+        $where[] = qsprintf(
+          $conn,
+          'event.importSourcePHID IS NULL');
+      }
+    }
+
     return $where;
   }
 
diff --git a/src/applications/calendar/storage/PhabricatorCalendarEvent.php b/src/applications/calendar/storage/PhabricatorCalendarEvent.php
index 07e041a9ce..c40afe443e 100644
--- a/src/applications/calendar/storage/PhabricatorCalendarEvent.php
+++ b/src/applications/calendar/storage/PhabricatorCalendarEvent.php
@@ -1124,6 +1124,19 @@ final class PhabricatorCalendarEvent extends PhabricatorCalendarDAO
       ->execute();
   }
 
+  public function getNotificationPHIDs() {
+    $phids = array();
+    if ($this->getPHID()) {
+      $phids[] = $this->getPHID();
+    }
+
+    if ($this->getSeriesParentPHID()) {
+      $phids[] = $this->getSeriesParentPHID();
+    }
+
+    return $phids;
+  }
+
 
 /* -(  Markup Interface  )--------------------------------------------------- */
 
diff --git a/src/applications/calendar/storage/PhabricatorCalendarNotification.php b/src/applications/calendar/storage/PhabricatorCalendarNotification.php
new file mode 100644
index 0000000000..46daaa2b3a
--- /dev/null
+++ b/src/applications/calendar/storage/PhabricatorCalendarNotification.php
@@ -0,0 +1,27 @@
+<?php
+
+final class PhabricatorCalendarNotification
+  extends PhabricatorCalendarDAO {
+
+  protected $eventPHID;
+  protected $utcInitialEpoch;
+  protected $targetPHID;
+  protected $didNotifyEpoch;
+
+  protected function getConfiguration() {
+    return array(
+      self::CONFIG_TIMESTAMPS => false,
+      self::CONFIG_COLUMN_SCHEMA => array(
+        'utcInitialEpoch' => 'epoch',
+        'didNotifyEpoch' => 'epoch',
+      ),
+      self::CONFIG_KEY_SCHEMA => array(
+        'key_notify' => array(
+          'columns' => array('eventPHID', 'utcInitialEpoch', 'targetPHID'),
+          'unique' => true,
+        ),
+      ),
+    ) + parent::getConfiguration();
+  }
+
+}