diff --git a/include/upgrader/streams/core/b26f29a6-1ee831c8.cleanup.sql b/include/upgrader/streams/core/b26f29a6-1ee831c8.cleanup.sql
index f56a5cb2c0d24deac939bc08b185cbdcc53119d1..553c33b955dabd62030821faab3c7b8d5d6bfed1 100644
--- a/include/upgrader/streams/core/b26f29a6-1ee831c8.cleanup.sql
+++ b/include/upgrader/streams/core/b26f29a6-1ee831c8.cleanup.sql
@@ -17,3 +17,6 @@ ALTER TABLE `%TABLE_PREFIX%staff`
 ALTER TABLE `%TABLE_PREFIX%user_account`
     DROP `timezone_id`,
     DROP `dst`;
+
+DELETE FROM `%TABLE_PREFIX%config`
+    WHERE `key` = 'enable_daylight_saving' AND `namespace` = 'core';
diff --git a/include/upgrader/streams/core/b26f29a6-1ee831c8.patch.sql b/include/upgrader/streams/core/b26f29a6-1ee831c8.patch.sql
index 2b9944add5fe0464ae9229f883d25135c491dac8..f99d3a28cce63de36e3db49839b9ac7a1fbed206 100644
--- a/include/upgrader/streams/core/b26f29a6-1ee831c8.patch.sql
+++ b/include/upgrader/streams/core/b26f29a6-1ee831c8.patch.sql
@@ -146,6 +146,27 @@ UPDATE `%TABLE_PREFIX%user_account` A1
         AND A3.`south` = 0)
     SET A1.`timezone` = A3.`olson_name`;
 
+-- Update system default timezone
+SET @default_timezone_id = (
+    SELECT `value` FROM `%TABLE_PREFIX%config` A1
+    WHERE A1.`key` = 'default_timezone_id'
+      AND A1.`namespace` = 'core'
+);
+SET @enable_daylight_saving = (
+    SELECT `value` FROM `%TABLE_PREFIX%config` A1
+    WHERE A1.`key` = 'enable_daylight_saving'
+      AND A1.`namespace` = 'core'
+);
+
+UPDATE `%TABLE_PREFIX%config` A1
+    JOIN `%TABLE_PREFIX%timezone` A2 ON (@default_timezone_id = A2.`id`)
+    JOIN `%TABLE_PREFIX%_timezones` A3 ON (A2.`offset` * 60 = A3.`offset`
+        AND @enable_daylight_saving = A3.`dst`
+        AND A3.`south` = 0)
+    SET A1.`value` = A3.`olson_name`
+    WHERE A1.`key` = 'default_timezone_id'
+      AND A1.`namespace` = 'core';
+
 DROP TABLE %TABLE_PREFIX%_timezones;
 
 ALTER TABLE `%TABLE_PREFIX%ticket`