diff --git a/sql/v01/11.create.client.sql b/sql/v01/11.create.client.sql
index e35a6ec..39a0758 100644
--- a/sql/v01/11.create.client.sql
+++ b/sql/v01/11.create.client.sql
@@ -174,28 +174,49 @@ CREATE TABLE member_email_address (
         ON DELETE CASCADE
 ) STRICT;
 
-CREATE TABLE area_commitment (
+CREATE TABLE area_commitment_contract (
     fbnr      INTEGER NOT NULL,
-    mgnr      INTEGER NOT NULL,
-
-    vtrgid    TEXT    NOT NULL,
-    cultid    TEXT             DEFAULT NULL,
-    area      INTEGER NOT NULL,
 
     kgnr      INTEGER NOT NULL,
-    gstnr     TEXT    NOT NULL,
     rdnr      INTEGER,
 
-    year_from INTEGER CHECK (year_from >= 1000 AND year_from <= 9999) DEFAULT NULL,
-    year_to   INTEGER CHECK (year_to   >= 1000 AND year_to   <= 9999) DEFAULT NULL,
-
     comment   TEXT             DEFAULT NULL,
     ctime     INTEGER NOT NULL DEFAULT (UNIXEPOCH()),
     mtime     INTEGER NOT NULL DEFAULT (UNIXEPOCH()),
     xtime     INTEGER          DEFAULT NULL,
     itime     INTEGER          DEFAULT NULL,
 
-    CONSTRAINT pk_area_commitment PRIMARY KEY (fbnr),
+    CONSTRAINT area_commitment_contract PRIMARY KEY (fbnr),
+    CONSTRAINT fk_area_commitment_contract_wb_kg FOREIGN KEY (kgnr) REFERENCES wb_kg (kgnr)
+        ON UPDATE CASCADE
+        ON DELETE RESTRICT,
+    CONSTRAINT fk_area_commitment_contract_wb_rd FOREIGN KEY (kgnr, rdnr) REFERENCES wb_rd (kgnr, rdnr)
+        ON UPDATE CASCADE
+        ON DELETE RESTRICT
+) STRICT;
+
+CREATE TABLE area_commitment (
+    fbnr      INTEGER NOT NULL,
+    revnr     INTEGER NOT NULL,
+    mgnr      INTEGER NOT NULL,
+
+    vtrgid    TEXT    NOT NULL,
+    cultid    TEXT             DEFAULT NULL,
+    area      INTEGER NOT NULL,
+    gstnr     TEXT    NOT NULL,
+
+    year_from INTEGER CHECK (year_from >= 1000 AND year_from <= 9999) DEFAULT NULL,
+    year_to   INTEGER CHECK (year_to   >= 1000 AND year_to   <= 9999) DEFAULT NULL,
+
+    ctime     INTEGER NOT NULL DEFAULT (UNIXEPOCH()),
+    mtime     INTEGER NOT NULL DEFAULT (UNIXEPOCH()),
+    xtime     INTEGER          DEFAULT NULL,
+    itime     INTEGER          DEFAULT NULL,
+
+    CONSTRAINT pk_area_commitment PRIMARY KEY (fbnr, revnr),
+    CONSTRAINT fk_area_commitment_area_commitment_contract FOREIGN KEY (fbnr) REFERENCES area_commitment_contract (fbnr)
+        ON UPDATE CASCADE
+        ON DELETE CASCADE,
     CONSTRAINT fk_area_commitment_member FOREIGN KEY (mgnr) REFERENCES member (mgnr)
         ON UPDATE CASCADE
         ON DELETE RESTRICT,
@@ -203,12 +224,6 @@ CREATE TABLE area_commitment (
         ON UPDATE CASCADE
         ON DELETE RESTRICT,
     CONSTRAINT fk_area_commitment_wine_cultivation FOREIGN KEY (cultid) REFERENCES wine_cultivation (cultid)
-        ON UPDATE CASCADE
-        ON DELETE RESTRICT,
-    CONSTRAINT fk_area_commitment_wb_kg FOREIGN KEY (kgnr) REFERENCES wb_kg (kgnr)
-        ON UPDATE CASCADE
-        ON DELETE RESTRICT,
-    CONSTRAINT fk_area_commitment_wb_rd FOREIGN KEY (kgnr, rdnr) REFERENCES wb_rd (kgnr, rdnr)
         ON UPDATE CASCADE
         ON DELETE RESTRICT
 ) STRICT;
diff --git a/sql/v01/20.create.timestamp-trigger.sql b/sql/v01/20.create.timestamp-trigger.sql
index b0b1072..3c20d6f 100644
--- a/sql/v01/20.create.timestamp-trigger.sql
+++ b/sql/v01/20.create.timestamp-trigger.sql
@@ -79,11 +79,41 @@ END;
 
 ----------------------------------------------------------------
 
+CREATE TRIGGER t_area_commitment_contract_i_ctime
+    AFTER INSERT ON area_commitment_contract FOR EACH ROW
+    WHEN (SELECT value FROM client_parameter WHERE param = 'ENABLE_TIME_TRIGGERS') = 1 AND NEW.ctime != UNIXEPOCH()
+BEGIN
+    UPDATE area_commitment_contract SET ctime = UNIXEPOCH() WHERE fbnr = NEW.fbnr;
+END;
+
+CREATE TRIGGER t_area_commitment_contract_u_ctime
+    BEFORE UPDATE ON area_commitment_contract FOR EACH ROW
+    WHEN (SELECT value FROM client_parameter WHERE param = 'ENABLE_TIME_TRIGGERS') = 1 AND OLD.ctime != NEW.ctime
+BEGIN
+    SELECT RAISE(ABORT, 'It is not allowed to change ctime');
+END;
+
+CREATE TRIGGER t_area_commitment_contract_i_mtime
+    AFTER INSERT ON area_commitment_contract FOR EACH ROW
+    WHEN (SELECT value FROM client_parameter WHERE param = 'ENABLE_TIME_TRIGGERS') = 1 AND NEW.mtime != UNIXEPOCH()
+BEGIN
+    UPDATE area_commitment_contract SET mtime = UNIXEPOCH() WHERE fbnr = NEW.fbnr;
+END;
+
+CREATE TRIGGER t_area_commitment_contract_u_mtime
+    AFTER UPDATE ON area_commitment_contract FOR EACH ROW
+    WHEN (SELECT value FROM client_parameter WHERE param = 'ENABLE_TIME_TRIGGERS') = 1 AND NEW.mtime != UNIXEPOCH()
+BEGIN
+    UPDATE area_commitment_contract SET mtime = UNIXEPOCH() WHERE fbnr = NEW.fbnr;
+END;
+
+----------------------------------------------------------------
+
 CREATE TRIGGER t_area_commitment_i_ctime
     AFTER INSERT ON area_commitment FOR EACH ROW
     WHEN (SELECT value FROM client_parameter WHERE param = 'ENABLE_TIME_TRIGGERS') = 1 AND NEW.ctime != UNIXEPOCH()
 BEGIN
-    UPDATE area_commitment SET ctime = UNIXEPOCH() WHERE fbnr = NEW.fbnr;
+    UPDATE area_commitment SET ctime = UNIXEPOCH() WHERE (fbnr, revnr) = (NEW.fbnr, NEW.revnr);
 END;
 
 CREATE TRIGGER t_area_commitment_u_ctime
@@ -97,14 +127,56 @@ CREATE TRIGGER t_area_commitment_i_mtime
     AFTER INSERT ON area_commitment FOR EACH ROW
     WHEN (SELECT value FROM client_parameter WHERE param = 'ENABLE_TIME_TRIGGERS') = 1 AND NEW.mtime != UNIXEPOCH()
 BEGIN
-    UPDATE area_commitment SET mtime = UNIXEPOCH() WHERE fbnr = NEW.fbnr;
+    UPDATE area_commitment SET mtime = UNIXEPOCH() WHERE (fbnr, revnr) = (NEW.fbnr, NEW.revnr);
 END;
 
 CREATE TRIGGER t_area_commitment_u_mtime
     AFTER UPDATE ON area_commitment FOR EACH ROW
     WHEN (SELECT value FROM client_parameter WHERE param = 'ENABLE_TIME_TRIGGERS') = 1 AND NEW.mtime != UNIXEPOCH()
 BEGIN
-    UPDATE area_commitment SET mtime = UNIXEPOCH() WHERE fbnr = NEW.fbnr;
+    UPDATE area_commitment SET mtime = UNIXEPOCH() WHERE (fbnr, revnr) = (NEW.fbnr, NEW.revnr);
+END;
+
+CREATE TRIGGER t_area_commitment_i_mtime_contract
+    AFTER INSERT ON area_commitment FOR EACH ROW
+    WHEN (SELECT value FROM client_parameter WHERE param = 'ENABLE_TIME_TRIGGERS') = 1
+BEGIN
+    UPDATE area_commitment_contract SET mtime = UNIXEPOCH() WHERE fbnr = NEW.fbnr;
+END;
+
+CREATE TRIGGER t_area_commitment_u_mtime_contract
+    AFTER UPDATE ON area_commitment FOR EACH ROW
+    WHEN (SELECT value FROM client_parameter WHERE param = 'ENABLE_TIME_TRIGGERS') = 1
+BEGIN
+    UPDATE area_commitment_contract SET mtime = UNIXEPOCH() WHERE fbnr = NEW.fbnr OR fbnr = OLD.fbnr;
+END;
+
+CREATE TRIGGER t_area_commitment_d_mtime_contract
+    AFTER DELETE ON area_commitment FOR EACH ROW
+    WHEN (SELECT value FROM client_parameter WHERE param = 'ENABLE_TIME_TRIGGERS') = 1
+BEGIN
+    UPDATE area_commitment_contract SET mtime = UNIXEPOCH() WHERE fbnr = OLD.fbnr;
+END;
+
+CREATE TRIGGER t_area_commitment_i_mtime_member
+    AFTER INSERT ON area_commitment FOR EACH ROW
+    WHEN (SELECT value FROM client_parameter WHERE param = 'ENABLE_TIME_TRIGGERS') = 1
+BEGIN
+    UPDATE member  SET mtime = UNIXEPOCH() WHERE mgnr = NEW.mgnr;
+END;
+
+CREATE TRIGGER t_area_commitment_u_mtime_member
+    AFTER UPDATE ON area_commitment FOR EACH ROW
+    WHEN (SELECT value FROM client_parameter WHERE param = 'ENABLE_TIME_TRIGGERS') = 1
+BEGIN
+    UPDATE member SET mtime = UNIXEPOCH() WHERE mgnr = NEW.mgnr OR mgnr = OLD.mgnr;
+END;
+
+CREATE TRIGGER t_area_commitment_d_mtime_member
+    AFTER DELETE ON area_commitment FOR EACH ROW
+    WHEN (SELECT value FROM client_parameter WHERE param = 'ENABLE_TIME_TRIGGERS') = 1
+BEGIN
+    UPDATE member SET mtime = UNIXEPOCH() WHERE mgnr = OLD.mgnr;
 END;
 
 ----------------------------------------------------------------
diff --git a/sql/v01/99.schema_version.sql b/sql/v01/99.schema_version.sql
index cd437ab..444196e 100644
--- a/sql/v01/99.schema_version.sql
+++ b/sql/v01/99.schema_version.sql
@@ -1,3 +1,3 @@
 
 -- This value MUST NOT be changed while other connections are open!
-PRAGMA schema_version = 3600;
+PRAGMA schema_version = 3800;