diff -pruN 3.5.2-1/debian/changelog 3.5.2-1ubuntu1/debian/changelog
--- 3.5.2-1/debian/changelog	2016-04-27 17:10:21.000000000 +0000
+++ 3.5.2-1ubuntu1/debian/changelog	2017-10-29 15:59:06.000000000 +0000
@@ -1,3 +1,9 @@
+php-sabre-vobject-3 (3.5.2-1ubuntu1) bionic; urgency=medium
+
+  * 0003-East-Sask.patch: Remove obsolete East-Saskatchewan timezone.
+
+ -- Adam Conrad <adconrad@ubuntu.com>  Sun, 29 Oct 2017 09:59:06 -0600
+
 php-sabre-vobject-3 (3.5.2-1) unstable; urgency=medium
 
   [ Visily Komrakov ]
diff -pruN 3.5.2-1/debian/control 3.5.2-1ubuntu1/debian/control
--- 3.5.2-1/debian/control	2016-04-27 17:08:55.000000000 +0000
+++ 3.5.2-1ubuntu1/debian/control	2017-10-29 15:59:06.000000000 +0000
@@ -1,7 +1,8 @@
 Source: php-sabre-vobject-3
 Section: php
 Priority: optional
-Maintainer: Debian PHP PEAR Maintainers <pkg-php-pear@lists.alioth.debian.org>
+Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>
+XSBC-Original-Maintainer: Debian PHP PEAR Maintainers <pkg-php-pear@lists.alioth.debian.org>
 Uploaders: David Prévot <taffit@debian.org>
 Build-Depends: debhelper (>= 9),
                help2man,
diff -pruN 3.5.2-1/debian/patches/0003-East-Sask.patch 3.5.2-1ubuntu1/debian/patches/0003-East-Sask.patch
--- 3.5.2-1/debian/patches/0003-East-Sask.patch	1970-01-01 00:00:00.000000000 +0000
+++ 3.5.2-1ubuntu1/debian/patches/0003-East-Sask.patch	2017-10-29 15:59:06.000000000 +0000
@@ -0,0 +1,14 @@
+Description: Remove obsolete East-Saskatchewan timezone.
+Author: Adam Conrad <adconrad@ubuntu.com>
+Last-Update: 2017-10-29
+
+--- php-sabre-vobject-3-3.5.2.orig/lib/timezonedata/php-bc.php
++++ php-sabre-vobject-3-3.5.2/lib/timezonedata/php-bc.php
+@@ -67,7 +67,6 @@ return array(
+     'Brazil/West',
+     'Canada/Atlantic',
+     'Canada/Central',
+-    'Canada/East-Saskatchewan',
+     'Canada/Eastern',
+     'Canada/Mountain',
+     'Canada/Newfoundland',
diff -pruN 3.5.2-1/debian/patches/series 3.5.2-1ubuntu1/debian/patches/series
--- 3.5.2-1/debian/patches/series	2016-04-27 17:08:57.000000000 +0000
+++ 3.5.2-1ubuntu1/debian/patches/series	2017-10-29 15:59:06.000000000 +0000
@@ -1,2 +1,3 @@
 0001-Use-homemade-autoloader.php.patch
 0002-Use-ClassLoader-from-Symfony-instead-of-autoLoader.patch
+0003-East-Sask.patch
diff -pruN 3.5.2-1/lib/timezonedata/php-bc.php 3.5.2-1ubuntu1/lib/timezonedata/php-bc.php
--- 3.5.2-1/lib/timezonedata/php-bc.php	2016-04-24 07:05:24.000000000 +0000
+++ 3.5.2-1ubuntu1/lib/timezonedata/php-bc.php	2017-10-29 18:10:41.000000000 +0000
@@ -67,7 +67,6 @@ return array(
     'Brazil/West',
     'Canada/Atlantic',
     'Canada/Central',
-    'Canada/East-Saskatchewan',
     'Canada/Eastern',
     'Canada/Mountain',
     'Canada/Newfoundland',
diff -pruN 3.5.2-1/.pc/0003-East-Sask.patch/lib/timezonedata/php-bc.php 3.5.2-1ubuntu1/.pc/0003-East-Sask.patch/lib/timezonedata/php-bc.php
--- 3.5.2-1/.pc/0003-East-Sask.patch/lib/timezonedata/php-bc.php	1970-01-01 00:00:00.000000000 +0000
+++ 3.5.2-1ubuntu1/.pc/0003-East-Sask.patch/lib/timezonedata/php-bc.php	2016-04-24 07:05:24.000000000 +0000
@@ -0,0 +1,153 @@
+<?php
+/**
+ * A list of additional PHP timezones that are returned by
+ * DateTimeZone::listIdentifiers(DateTimeZone::ALL_WITH_BC)
+ * valid for new DateTimeZone()
+ *
+ * This list does not include those timezone identifiers that we have to map to
+ * a different identifier for some PHP versions (see php-workaround.php).
+ *
+ * Instead of using DateTimeZone::listIdentifiers(DateTimeZone::ALL_WITH_BC)
+ * directly, we use this file because DateTimeZone::ALL_WITH_BC is not properly
+ * supported by all PHP version and HHVM.
+ *
+ * @copyright Copyright (C) fruux GmbH (https://fruux.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+return array(
+    'Africa/Asmera',
+    'Africa/Timbuktu',
+    'America/Argentina/ComodRivadavia',
+    'America/Atka',
+    'America/Buenos_Aires',
+    'America/Catamarca',
+    'America/Coral_Harbour',
+    'America/Cordoba',
+    'America/Ensenada',
+    'America/Fort_Wayne',
+    'America/Indianapolis',
+    'America/Jujuy',
+    'America/Knox_IN',
+    'America/Louisville',
+    'America/Mendoza',
+    'America/Montreal',
+    'America/Porto_Acre',
+    'America/Rosario',
+    'America/Shiprock',
+    'America/Virgin',
+    'Antarctica/South_Pole',
+    'Asia/Ashkhabad',
+    'Asia/Calcutta',
+    'Asia/Chungking',
+    'Asia/Dacca',
+    'Asia/Istanbul',
+    'Asia/Katmandu',
+    'Asia/Macao',
+    'Asia/Saigon',
+    'Asia/Tel_Aviv',
+    'Asia/Thimbu',
+    'Asia/Ujung_Pandang',
+    'Asia/Ulan_Bator',
+    'Atlantic/Faeroe',
+    'Atlantic/Jan_Mayen',
+    'Australia/ACT',
+    'Australia/Canberra',
+    'Australia/LHI',
+    'Australia/North',
+    'Australia/NSW',
+    'Australia/Queensland',
+    'Australia/South',
+    'Australia/Tasmania',
+    'Australia/Victoria',
+    'Australia/West',
+    'Australia/Yancowinna',
+    'Brazil/Acre',
+    'Brazil/DeNoronha',
+    'Brazil/East',
+    'Brazil/West',
+    'Canada/Atlantic',
+    'Canada/Central',
+    'Canada/East-Saskatchewan',
+    'Canada/Eastern',
+    'Canada/Mountain',
+    'Canada/Newfoundland',
+    'Canada/Pacific',
+    'Canada/Saskatchewan',
+    'Canada/Yukon',
+    'CET',
+    'Chile/Continental',
+    'Chile/EasterIsland',
+    'EET',
+    'EST',
+    'Etc/GMT',
+    'Etc/GMT+0',
+    'Etc/GMT+1',
+    'Etc/GMT+10',
+    'Etc/GMT+11',
+    'Etc/GMT+12',
+    'Etc/GMT+2',
+    'Etc/GMT+3',
+    'Etc/GMT+4',
+    'Etc/GMT+5',
+    'Etc/GMT+6',
+    'Etc/GMT+7',
+    'Etc/GMT+8',
+    'Etc/GMT+9',
+    'Etc/GMT-0',
+    'Etc/GMT-1',
+    'Etc/GMT-10',
+    'Etc/GMT-11',
+    'Etc/GMT-12',
+    'Etc/GMT-13',
+    'Etc/GMT-14',
+    'Etc/GMT-2',
+    'Etc/GMT-3',
+    'Etc/GMT-4',
+    'Etc/GMT-5',
+    'Etc/GMT-6',
+    'Etc/GMT-7',
+    'Etc/GMT-8',
+    'Etc/GMT-9',
+    'Etc/GMT0',
+    'Etc/Greenwich',
+    'Etc/UCT',
+    'Etc/Universal',
+    'Etc/UTC',
+    'Etc/Zulu',
+    'Europe/Belfast',
+    'Europe/Nicosia',
+    'Europe/Tiraspol',
+    'GB',
+    'GMT',
+    'GMT+0',
+    'GMT-0',
+    'HST',
+    'MET',
+    'Mexico/BajaNorte',
+    'Mexico/BajaSur',
+    'Mexico/General',
+    'MST',
+    'NZ',
+    'Pacific/Ponape',
+    'Pacific/Samoa',
+    'Pacific/Truk',
+    'Pacific/Yap',
+    'PRC',
+    'ROC',
+    'ROK',
+    'UCT',
+    'US/Alaska',
+    'US/Aleutian',
+    'US/Arizona',
+    'US/Central',
+    'US/East-Indiana',
+    'US/Eastern',
+    'US/Hawaii',
+    'US/Indiana-Starke',
+    'US/Michigan',
+    'US/Mountain',
+    'US/Pacific',
+    'US/Pacific-New',
+    'US/Samoa',
+    'WET',
+);
diff -pruN 3.5.2-1/.pc/applied-patches 3.5.2-1ubuntu1/.pc/applied-patches
--- 3.5.2-1/.pc/applied-patches	2017-10-29 18:10:41.260228876 +0000
+++ 3.5.2-1ubuntu1/.pc/applied-patches	2017-10-29 18:10:41.472234733 +0000
@@ -1,2 +1,3 @@
 0001-Use-homemade-autoloader.php.patch
 0002-Use-ClassLoader-from-Symfony-instead-of-autoLoader.patch
+0003-East-Sask.patch