diff --git a/commons/src/test/java/com/powsybl/dynawo/commons/AbstractDynawoCommonsTest.java b/commons/src/test/java/com/powsybl/dynawo/commons/AbstractDynawoCommonsTest.java
index e71e5cb22..3f74ca004 100644
--- a/commons/src/test/java/com/powsybl/dynawo/commons/AbstractDynawoCommonsTest.java
+++ b/commons/src/test/java/com/powsybl/dynawo/commons/AbstractDynawoCommonsTest.java
@@ -12,25 +12,30 @@
 import com.powsybl.iidm.xml.NetworkXml;
 
 import java.io.IOException;
+import java.io.InputStream;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.Objects;
 
 import static com.powsybl.commons.test.ComparisonUtils.compareTxt;
-import static org.junit.Assert.assertNotNull;
 
 /**
  * @author Florian Dupuy <florian.dupuy at rte-france.com>
  */
 public abstract class AbstractDynawoCommonsTest extends AbstractConverterTest {
 
+    protected void compare(String expectedIidmResource, Network actual) throws IOException {
+        InputStream expected = Objects.requireNonNull(getClass().getResourceAsStream(expectedIidmResource));
+        compareTxt(expected, getInputStream(actual, tmpDir.resolve("actual.xiidm")));
+    }
+
     protected void compare(Network expected, Network actual) throws IOException {
-        Path pExpected = tmpDir.resolve("expected.xiidm");
-        assertNotNull(pExpected);
-        Path pActual = tmpDir.resolve("actual.xiidm");
-        assertNotNull(pActual);
-        NetworkXml.write(expected, pExpected);
-        actual.setCaseDate(expected.getCaseDate());
-        NetworkXml.write(actual, pActual);
-        compareTxt(Files.newInputStream(pExpected), Files.newInputStream(pActual));
+        compareTxt(getInputStream(expected, tmpDir.resolve("expected.xiidm")),
+                getInputStream(actual, tmpDir.resolve("actual.xiidm")));
+    }
+
+    private InputStream getInputStream(Network n, Path path) throws IOException {
+        NetworkXml.write(n, path);
+        return Files.newInputStream(path);
     }
 }
diff --git a/commons/src/test/java/com/powsybl/dynawo/commons/LoadsMergerTest.java b/commons/src/test/java/com/powsybl/dynawo/commons/LoadsMergerTest.java
index 0ceb461e8..a90bcd188 100644
--- a/commons/src/test/java/com/powsybl/dynawo/commons/LoadsMergerTest.java
+++ b/commons/src/test/java/com/powsybl/dynawo/commons/LoadsMergerTest.java
@@ -22,8 +22,7 @@ public class LoadsMergerTest extends AbstractDynawoCommonsTest {
     @Test
     public void multiBusesInVoltageLevel() throws IOException {
         Network network = TestNetworkFactory.createMultiBusesVoltageLevelNetwork();
-        Network expectedIidm = Network.read("mergedLoadsMultiBusesVl.xiidm", getClass().getResourceAsStream("/mergedLoadsMultiBusesVl.xiidm"));
-        compare(expectedIidm, LoadsMerger.mergeLoads(network));
+        compare("/mergedLoadsMultiBusesVl.xiidm", LoadsMerger.mergeLoads(network));
     }
 
     @Test
@@ -32,8 +31,7 @@ public void mergeLoadsPpQp() throws IOException {
                 new LoadState(36.1, 4.0, 36.0, 4.0),
                 new LoadState(10.1, 7.2, 10.3, 7.5));
         Network network = TestNetworkFactory.createMultiLoadsBusesNetwork(loadStates);
-        Network expectedIidm = Network.read("mergedLoadsPpQp.xiidm", getClass().getResourceAsStream("/mergedLoadsPpQp.xiidm"));
-        compare(expectedIidm, LoadsMerger.mergeLoads(network));
+        compare("/mergedLoadsPpQp.xiidm", LoadsMerger.mergeLoads(network));
     }
 
     @Test
@@ -42,8 +40,7 @@ public void mergeLoadsPpQn() throws IOException {
                 new LoadState(36.1, -4.0, 36.0, -4.0),
                 new LoadState(10.1, -7.2, 10.3, -7.5));
         Network network = TestNetworkFactory.createMultiLoadsBusesNetwork(loadStates);
-        Network expectedIidm = Network.read("mergedLoadsPpQn.xiidm", getClass().getResourceAsStream("/mergedLoadsPpQn.xiidm"));
-        compare(expectedIidm, LoadsMerger.mergeLoads(network));
+        compare("/mergedLoadsPpQn.xiidm", LoadsMerger.mergeLoads(network));
     }
 
     @Test
@@ -52,8 +49,7 @@ public void mergeLoadsPnQn() throws IOException {
                 new LoadState(-36.1, -4.0, -36.0, -4.0),
                 new LoadState(-10.1, -7.2, -10.3, -7.5));
         Network network = TestNetworkFactory.createMultiLoadsBusesNetwork(loadStates);
-        Network expectedIidm = Network.read("mergedLoadsPnQn.xiidm", getClass().getResourceAsStream("/mergedLoadsPnQn.xiidm"));
-        compare(expectedIidm, LoadsMerger.mergeLoads(network));
+        compare("/mergedLoadsPnQn.xiidm", LoadsMerger.mergeLoads(network));
     }
 
     @Test
@@ -62,8 +58,7 @@ public void mergeLoadsPnQp() throws IOException {
                 new LoadState(-36.1, 4.0, -36.0, 4.0),
                 new LoadState(-10.1, 7.2, -10.3, 7.5));
         Network network = TestNetworkFactory.createMultiLoadsBusesNetwork(loadStates);
-        Network expectedIidm = Network.read("mergedLoadsPnQp.xiidm", getClass().getResourceAsStream("/mergedLoadsPnQp.xiidm"));
-        compare(expectedIidm, LoadsMerger.mergeLoads(network));
+        compare("/mergedLoadsPnQp.xiidm", LoadsMerger.mergeLoads(network));
     }
 
     @Test
@@ -76,8 +71,7 @@ public void mergeThreeLoadsGroups() throws IOException {
                 new LoadState(10.1, -7.2, 10.3, -7.5),
                 new LoadState(-10.1, -7.2, -10.3, -7.5));
         Network network = TestNetworkFactory.createMultiLoadsBusesNetwork(loadStates);
-        Network expectedIidm = Network.read("mergedThreeLoadsGroups.xiidm", getClass().getResourceAsStream("/mergedThreeLoadsGroups.xiidm"));
-        compare(expectedIidm, LoadsMerger.mergeLoads(network));
+        compare("/mergedThreeLoadsGroups.xiidm", LoadsMerger.mergeLoads(network));
     }
 
     @Test
@@ -88,7 +82,6 @@ public void nonMergeableLoads() throws IOException {
                 new LoadState(36.1, -1.0, 16.0, -4.0),
                 new LoadState(-5.5, -2.0, -46.0, -5.0));
         Network network = TestNetworkFactory.createMultiLoadsBusesNetwork(loadStates);
-        Network expectedIidm = Network.read("nonMergeableLoads.xiidm", getClass().getResourceAsStream("/nonMergeableLoads.xiidm"));
-        compare(expectedIidm, LoadsMerger.mergeLoads(network));
+        compare("/nonMergeableLoads.xiidm", LoadsMerger.mergeLoads(network));
     }
 }
diff --git a/commons/src/test/java/com/powsybl/dynawo/commons/TestNetworkFactory.java b/commons/src/test/java/com/powsybl/dynawo/commons/TestNetworkFactory.java
index e50038a62..b43b6aeb9 100644
--- a/commons/src/test/java/com/powsybl/dynawo/commons/TestNetworkFactory.java
+++ b/commons/src/test/java/com/powsybl/dynawo/commons/TestNetworkFactory.java
@@ -8,6 +8,7 @@
 package com.powsybl.dynawo.commons;
 
 import com.powsybl.iidm.network.*;
+import org.joda.time.DateTime;
 
 import java.util.List;
 
@@ -20,7 +21,8 @@ private TestNetworkFactory() {
     }
 
     static Network createMultiBusesVoltageLevelNetwork() {
-        Network network = Network.create("multiBusesVl", "test");
+        Network network = Network.create("multiBusesVl", "test")
+                .setCaseDate(DateTime.parse("2023-02-17T05:41:11.194+01:00"));
         Substation s = network.newSubstation().setId("substation").add();
 
         VoltageLevel vl1 = s.newVoltageLevel().setId("vl1").setNominalV(250).setTopologyKind(TopologyKind.NODE_BREAKER).add();
@@ -67,7 +69,8 @@ static Network createMultiBusesVoltageLevelNetwork() {
      * @return the test network generated
      */
     static Network createMultiLoadsBusesNetwork(List<LoadState> loadStates) {
-        Network network = Network.create("multiLoads", "test");
+        Network network = Network.create("multiLoads", "test")
+                .setCaseDate(DateTime.parse("2023-02-17T05:41:11.194+01:00"));
         Substation s = network.newSubstation().setId("substation").add();
 
         // First node breaker voltage level