diff --git a/chrono/agendas/migrations/0052_event_date_range_constraint.py b/chrono/agendas/migrations/0052_event_date_range_constraint.py
index 33c9cfb5..a07e6e3e 100644
--- a/chrono/agendas/migrations/0052_event_date_range_constraint.py
+++ b/chrono/agendas/migrations/0052_event_date_range_constraint.py
@@ -1,73 +1,25 @@
+import os
+
 from django.db import migrations, transaction
 from django.db.utils import InternalError, OperationalError, ProgrammingError
 
-sql_forwards = """
+with open(
+    os.path.join(
+        os.path.dirname(os.path.realpath(__file__)),
+        '..',
+        'sql',
+        'event_triggers_for_tstzrange_constraint.sql',
+    )
+) as sql_file:
+    sql_triggers = sql_file.read()
+
+sql_forwards = (
+    """
 -- Add technical columns
 ALTER TABLE agendas_event ADD COLUMN _end_datetime TIMESTAMP WITH TIME ZONE;
 ALTER TABLE agendas_event ADD COLUMN _ignore_reason CHARACTER VARYING(20);
 
--- trigger and procedure to maintain _ignore_reason from bookings
-CREATE OR REPLACE FUNCTION set_ignore_reason() RETURNS TRIGGER AS $$
-    BEGIN
-        IF (TG_OP = 'INSERT') THEN
-            IF NEW.cancellation_datetime IS NOT NULL THEN
-                UPDATE agendas_event SET _ignore_reason = 'cancel' WHERE id = NEW.event_id;
-            END IF;
-            RETURN NEW;
-        ELSE
-            PERFORM 1 FROM agendas_booking b WHERE b.event_id = OLD.event_id AND b.cancellation_datetime IS NOT NULL;
-            IF FOUND THEN
-                UPDATE agendas_event SET _ignore_reason = 'cancel' WHERE id = OLD.event_id;
-            ELSE
-                UPDATE agendas_event SET _ignore_reason = NULL WHERE id = OLD.event_id;
-            END IF;
-            IF (TG_OP = 'UPDATE') THEN
-                RETURN NEW;
-            ELSE
-                RETURN OLD;
-            END IF;
-        END IF;
-    END;
-$$ LANGUAGE plpgsql;
-
-DROP TRIGGER IF EXISTS set_ignore_reason_trg ON agendas_booking;
-CREATE TRIGGER set_ignore_reason_trg
-    AFTER INSERT OR UPDATE OR DELETE ON agendas_booking
-    FOR EACH ROW
-    EXECUTE PROCEDURE set_ignore_reason();
-
--- triggers to maintain _end_datetime
-CREATE OR REPLACE FUNCTION update_duration() RETURNS TRIGGER AS $$
-    BEGIN
-        UPDATE agendas_event SET _end_datetime = start_datetime + (NEW.duration ||' minutes')::interval WHERE meeting_type_id = NEW.id;
-        RETURN NEW;
-    END;
-$$ LANGUAGE plpgsql;
-
-DROP TRIGGER IF EXISTS update_duration_trg ON agendas_meetingtype;
-CREATE TRIGGER update_duration_trg
-    AFTER UPDATE ON agendas_meetingtype
-    FOR EACH ROW
-    WHEN (OLD.duration != NEW.duration)
-    EXECUTE PROCEDURE update_duration();
-
-CREATE OR REPLACE FUNCTION set_end_datetime() RETURNS TRIGGER AS $$
-    BEGIN
-        IF NEW.meeting_type_id IS NULL THEN
-            NEW._end_datetime = NULL;
-        ELSE
-            NEW._end_datetime = NEW.start_datetime + ((
-                SELECT mt.duration FROM agendas_meetingtype mt WHERE mt.id = NEW.meeting_type_id) ||' minutes')::interval;
-        END IF;
-        RETURN NEW;
-    END;
-$$ LANGUAGE plpgsql;
-
-DROP TRIGGER IF EXISTS set_end_datetime_trg ON agendas_event;
-CREATE TRIGGER set_end_datetime_trg
-    BEFORE INSERT OR UPDATE ON agendas_event
-    FOR EACH ROW
-    EXECUTE PROCEDURE set_end_datetime();
+%s
 
 -- Init legacy
 UPDATE agendas_event SET _ignore_reason = 'history';
@@ -80,6 +32,8 @@ FROM
 WHERE
     agendas_meetingtype.id = agendas_event.meeting_type_id;
 """
+    % sql_triggers
+)
 
 sql_backwards = """
 DROP TRIGGER IF EXISTS set_ignore_reason_trg ON agendas_booking;
diff --git a/chrono/agendas/sql/event_triggers_for_tstzrange_constraint.sql b/chrono/agendas/sql/event_triggers_for_tstzrange_constraint.sql
new file mode 100644
index 00000000..40209385
--- /dev/null
+++ b/chrono/agendas/sql/event_triggers_for_tstzrange_constraint.sql
@@ -0,0 +1,62 @@
+-- trigger and procedure to maintain _ignore_reason from bookings
+CREATE OR REPLACE FUNCTION set_ignore_reason() RETURNS TRIGGER AS $$
+    BEGIN
+        IF (TG_OP = 'INSERT') THEN
+            IF NEW.cancellation_datetime IS NOT NULL THEN
+                UPDATE agendas_event SET _ignore_reason = 'cancel' WHERE id = NEW.event_id;
+            END IF;
+            RETURN NEW;
+        ELSE
+            PERFORM 1 FROM agendas_booking b WHERE b.event_id = OLD.event_id AND b.cancellation_datetime IS NOT NULL;
+            IF FOUND THEN
+                UPDATE agendas_event SET _ignore_reason = 'cancel' WHERE id = OLD.event_id;
+            ELSE
+                UPDATE agendas_event SET _ignore_reason = NULL WHERE id = OLD.event_id;
+            END IF;
+            IF (TG_OP = 'UPDATE') THEN
+                RETURN NEW;
+            ELSE
+                RETURN OLD;
+            END IF;
+        END IF;
+    END;
+$$ LANGUAGE plpgsql;
+
+DROP TRIGGER IF EXISTS set_ignore_reason_trg ON agendas_booking;
+CREATE TRIGGER set_ignore_reason_trg
+    AFTER INSERT OR UPDATE OR DELETE ON agendas_booking
+    FOR EACH ROW
+    EXECUTE PROCEDURE set_ignore_reason();
+
+-- triggers to maintain _end_datetime
+CREATE OR REPLACE FUNCTION update_duration() RETURNS TRIGGER AS $$
+    BEGIN
+        UPDATE agendas_event SET _end_datetime = start_datetime + (NEW.duration ||' minutes')::interval WHERE meeting_type_id = NEW.id;
+        RETURN NEW;
+    END;
+$$ LANGUAGE plpgsql;
+
+DROP TRIGGER IF EXISTS update_duration_trg ON agendas_meetingtype;
+CREATE TRIGGER update_duration_trg
+    AFTER UPDATE ON agendas_meetingtype
+    FOR EACH ROW
+    WHEN (OLD.duration != NEW.duration)
+    EXECUTE PROCEDURE update_duration();
+
+CREATE OR REPLACE FUNCTION set_end_datetime() RETURNS TRIGGER AS $$
+    BEGIN
+        IF NEW.meeting_type_id IS NULL THEN
+            NEW._end_datetime = NULL;
+        ELSE
+            NEW._end_datetime = NEW.start_datetime + ((
+                SELECT mt.duration FROM agendas_meetingtype mt WHERE mt.id = NEW.meeting_type_id) ||' minutes')::interval;
+        END IF;
+        RETURN NEW;
+    END;
+$$ LANGUAGE plpgsql;
+
+DROP TRIGGER IF EXISTS set_end_datetime_trg ON agendas_event;
+CREATE TRIGGER set_end_datetime_trg
+    BEFORE INSERT OR UPDATE ON agendas_event
+    FOR EACH ROW
+    EXECUTE PROCEDURE set_end_datetime();