diff --git a/Elwig/Helpers/AppDbUpdater.cs b/Elwig/Helpers/AppDbUpdater.cs
index bdaffcb..6933870 100644
--- a/Elwig/Helpers/AppDbUpdater.cs
+++ b/Elwig/Helpers/AppDbUpdater.cs
@@ -9,7 +9,7 @@ namespace Elwig.Helpers {
     public static class AppDbUpdater {
 
         // Don't forget to update value in Tests/fetch-resources.bat!
-        public static readonly int RequiredSchemaVersion = 36;
+        public static readonly int RequiredSchemaVersion = 37;
 
         private static int VersionOffset = 0;
 
diff --git a/Elwig/Resources/Sql/34-35.sql b/Elwig/Resources/Sql/34-35.sql
index b0081ff..41c5888 100644
--- a/Elwig/Resources/Sql/34-35.sql
+++ b/Elwig/Resources/Sql/34-35.sql
@@ -1,6 +1,8 @@
 -- schema version 34 to 35
 
+UPDATE client_parameter SET value = '0' WHERE param = 'ENABLE_TIME_TRIGGERS';
 ALTER TABLE delivery_part ADD COLUMN unloading TEXT DEFAULT NULL;
 UPDATE delivery_part SET unloading = 'pumped' WHERE lesewagen;
 UPDATE delivery_part SET unloading = 'box' WHERE (SELECT zwstid IN ('H','S') FROM delivery d WHERE (d.year, d.did) = (delivery_part.year, delivery_part.did));
 ALTER TABLE delivery_part DROP COLUMN lesewagen;
+UPDATE client_parameter SET value = '1' WHERE param = 'ENABLE_TIME_TRIGGERS';
diff --git a/Elwig/Resources/Sql/36-37.sql b/Elwig/Resources/Sql/36-37.sql
new file mode 100644
index 0000000..9170d72
--- /dev/null
+++ b/Elwig/Resources/Sql/36-37.sql
@@ -0,0 +1,12 @@
+-- schema version 36 to 37
+
+UPDATE client_parameter SET value = '0' WHERE param = 'ENABLE_TIME_TRIGGERS';
+
+-- fix old deliveries
+UPDATE delivery         SET xtime = NULL, mtime = ctime WHERE year <= 2022 AND mtime >= 1768521600 AND mtime < 1772323200;
+UPDATE delivery_part    SET xtime = NULL, mtime = ctime WHERE year <= 2022 AND mtime >= 1768521600 AND mtime < 1772323200;
+-- clear xtime at one laptop to force updates from this one
+UPDATE delivery         SET xtime = NULL WHERE year >= 2023 AND xtime >= 1771200000 AND xtime < 1771286400;
+UPDATE delivery_part    SET xtime = NULL WHERE year >= 2023 AND xtime >= 1771200000 AND xtime < 1771286400;
+
+UPDATE client_parameter SET value = '1' WHERE param = 'ENABLE_TIME_TRIGGERS';