diff --git a/tests/nexus/test_1_1_9_2_10.cpp b/tests/nexus/test_1_1_9_2_10.cpp
index 5342e1ee2..ae9341ef5 100644
--- a/tests/nexus/test_1_1_9_2_10.cpp
+++ b/tests/nexus/test_1_1_9_2_10.cpp
@@ -200,8 +200,8 @@ void Test9_2_10(void)
         datasetInfo.Set<MeshCoP::Dataset::kPanId>(kPrimaryPanId);
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kLeaderActiveTimestamp);
-            timestamp.SetTicks(0);
             datasetInfo.Set<MeshCoP::Dataset::kActiveTimestamp>(timestamp);
         }
         leader.Get<MeshCoP::ActiveDatasetManager>().SaveLocal(datasetInfo);
@@ -262,14 +262,14 @@ void Test9_2_10(void)
         SuccessOrQuit(Tlv::Append<MeshCoP::CommissionerSessionIdTlv>(*message, sessionId));
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kActiveTimestampStep2);
-            timestamp.SetTicks(0);
             SuccessOrQuit(Tlv::Append<MeshCoP::ActiveTimestampTlv>(*message, timestamp));
         }
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kPendingTimestampStep2);
-            timestamp.SetTicks(0);
             SuccessOrQuit(Tlv::Append<MeshCoP::PendingTimestampTlv>(*message, timestamp));
         }
         SuccessOrQuit(Tlv::Append<MeshCoP::DelayTimerTlv>(*message, kDelayTimerStep2));
diff --git a/tests/nexus/test_1_1_9_2_15.cpp b/tests/nexus/test_1_1_9_2_15.cpp
index 747fc5ae8..0f8bde26f 100644
--- a/tests/nexus/test_1_1_9_2_15.cpp
+++ b/tests/nexus/test_1_1_9_2_15.cpp
@@ -144,14 +144,14 @@ void SendPendingSet(Node           &aCommissioner,
     SuccessOrQuit(Tlv::Append<MeshCoP::CommissionerSessionIdTlv>(*message, aSessionId));
     {
         MeshCoP::Timestamp timestamp;
+        timestamp.Clear();
         timestamp.SetSeconds(aActiveTimestamp);
-        timestamp.SetTicks(0);
         SuccessOrQuit(Tlv::Append<MeshCoP::ActiveTimestampTlv>(*message, timestamp));
     }
     {
         MeshCoP::Timestamp timestamp;
+        timestamp.Clear();
         timestamp.SetSeconds(aPendingTimestamp);
-        timestamp.SetTicks(0);
         SuccessOrQuit(Tlv::Append<MeshCoP::PendingTimestampTlv>(*message, timestamp));
     }
     {
diff --git a/tests/nexus/test_1_1_9_2_16.cpp b/tests/nexus/test_1_1_9_2_16.cpp
index f95388a11..d556bd1f0 100644
--- a/tests/nexus/test_1_1_9_2_16.cpp
+++ b/tests/nexus/test_1_1_9_2_16.cpp
@@ -262,14 +262,14 @@ void Test9_2_16(void)
         SuccessOrQuit(Tlv::Append<MeshCoP::CommissionerSessionIdTlv>(*message, sessionId));
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kActiveTimestampStep3);
-            timestamp.SetTicks(0);
             SuccessOrQuit(Tlv::Append<MeshCoP::ActiveTimestampTlv>(*message, timestamp));
         }
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kPendingTimestampStep3);
-            timestamp.SetTicks(0);
             SuccessOrQuit(Tlv::Append<MeshCoP::PendingTimestampTlv>(*message, timestamp));
         }
         {
@@ -415,14 +415,14 @@ void Test9_2_16(void)
         SuccessOrQuit(Tlv::Append<MeshCoP::CommissionerSessionIdTlv>(*message, sessionId));
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kActiveTimestampStep11);
-            timestamp.SetTicks(0);
             SuccessOrQuit(Tlv::Append<MeshCoP::ActiveTimestampTlv>(*message, timestamp));
         }
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kPendingTimestampStep11);
-            timestamp.SetTicks(0);
             SuccessOrQuit(Tlv::Append<MeshCoP::PendingTimestampTlv>(*message, timestamp));
         }
         {
@@ -478,8 +478,8 @@ void Test9_2_16(void)
         SuccessOrQuit(Tlv::Append<MeshCoP::CommissionerSessionIdTlv>(*message, sessionId));
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kActiveTimestampStep13);
-            timestamp.SetTicks(0);
             SuccessOrQuit(Tlv::Append<MeshCoP::ActiveTimestampTlv>(*message, timestamp));
         }
         SuccessOrQuit(Tlv::Append<MeshCoP::NetworkNameTlv>(*message, kNetworkNameStep13));
diff --git a/tests/nexus/test_1_1_9_2_17.cpp b/tests/nexus/test_1_1_9_2_17.cpp
index 21d86fa5b..a4522cbae 100644
--- a/tests/nexus/test_1_1_9_2_17.cpp
+++ b/tests/nexus/test_1_1_9_2_17.cpp
@@ -180,8 +180,8 @@ void Test9_2_17(void)
         }
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kLeader1Timestamp);
-            timestamp.SetTicks(0);
             datasetInfo.Set<MeshCoP::Dataset::kActiveTimestamp>(timestamp);
         }
         datasetInfo.Set<MeshCoP::Dataset::kChannelMask>((1 << kPrimaryChannel) | (1 << kSecondaryChannel));
@@ -204,8 +204,8 @@ void Test9_2_17(void)
         }
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kLeader2Timestamp);
-            timestamp.SetTicks(0);
             datasetInfo.Set<MeshCoP::Dataset::kActiveTimestamp>(timestamp);
         }
 
diff --git a/tests/nexus/test_1_1_9_2_18.cpp b/tests/nexus/test_1_1_9_2_18.cpp
index 4606035f6..53469f825 100644
--- a/tests/nexus/test_1_1_9_2_18.cpp
+++ b/tests/nexus/test_1_1_9_2_18.cpp
@@ -170,6 +170,7 @@ void Test9_2_18(void)
     SuccessOrQuit(datasetInfo.GenerateRandom(leader.GetInstance()));
     {
         MeshCoP::Timestamp timestamp;
+        timestamp.Clear();
         timestamp.SetSeconds(1);
         datasetInfo.Set<MeshCoP::Dataset::kActiveTimestamp>(timestamp);
     }
@@ -238,6 +239,7 @@ void Test9_2_18(void)
     activeDatasetInfo.Clear();
     {
         MeshCoP::Timestamp timestamp;
+        timestamp.Clear();
         timestamp.SetSeconds(kActiveTimestamp20000);
         activeDatasetInfo.Set<MeshCoP::Dataset::kActiveTimestamp>(timestamp);
     }
@@ -291,6 +293,7 @@ void Test9_2_18(void)
     pendingDatasetInfo1.Clear();
     {
         MeshCoP::Timestamp timestamp;
+        timestamp.Clear();
         timestamp.SetSeconds(kPendingTimestamp20);
         pendingDatasetInfo1.Set<MeshCoP::Dataset::kPendingTimestamp>(timestamp);
         timestamp.SetSeconds(kActiveTimestamp20);
@@ -349,6 +352,7 @@ void Test9_2_18(void)
     pendingDatasetInfo2.Clear();
     {
         MeshCoP::Timestamp timestamp;
+        timestamp.Clear();
         timestamp.SetSeconds(kPendingTimestamp20);
         pendingDatasetInfo2.Set<MeshCoP::Dataset::kPendingTimestamp>(timestamp);
         timestamp.SetSeconds(kActiveTimestamp20);
diff --git a/tests/nexus/test_1_1_9_2_4.cpp b/tests/nexus/test_1_1_9_2_4.cpp
index 87827de71..5d7ec0370 100644
--- a/tests/nexus/test_1_1_9_2_4.cpp
+++ b/tests/nexus/test_1_1_9_2_4.cpp
@@ -344,8 +344,8 @@ void RunTest9_2_4(Topology aTopology, const char *aJsonFile)
         SuccessOrQuit(Tlv::Append<MeshCoP::CommissionerSessionIdTlv>(*message, sessionId));
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kActiveTimestampStep2);
-            timestamp.SetTicks(0);
             SuccessOrQuit(Tlv::Append<MeshCoP::ActiveTimestampTlv>(*message, timestamp));
         }
         SuccessOrQuit(Tlv::AppendTlv(*message, MeshCoP::Tlv::kChannelMask, kChannelMask, sizeof(kChannelMask)));
@@ -446,8 +446,8 @@ void RunTest9_2_4(Topology aTopology, const char *aJsonFile)
         SuccessOrQuit(Tlv::Append<MeshCoP::CommissionerSessionIdTlv>(*message, sessionId));
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kActiveTimestampStep6);
-            timestamp.SetTicks(0);
             SuccessOrQuit(Tlv::Append<MeshCoP::ActiveTimestampTlv>(*message, timestamp));
         }
         SuccessOrQuit(Tlv::Append<MeshCoP::ChannelTlv>(*message, MeshCoP::ChannelTlvValue(0, kSecondaryChannel)));
@@ -510,8 +510,8 @@ void RunTest9_2_4(Topology aTopology, const char *aJsonFile)
         SuccessOrQuit(Tlv::Append<MeshCoP::CommissionerSessionIdTlv>(*message, sessionId));
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kActiveTimestampStep8);
-            timestamp.SetTicks(0);
             SuccessOrQuit(Tlv::Append<MeshCoP::ActiveTimestampTlv>(*message, timestamp));
         }
         SuccessOrQuit(
@@ -579,8 +579,8 @@ void RunTest9_2_4(Topology aTopology, const char *aJsonFile)
         SuccessOrQuit(Tlv::Append<MeshCoP::CommissionerSessionIdTlv>(*message, sessionId));
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kActiveTimestampStep10);
-            timestamp.SetTicks(0);
             SuccessOrQuit(Tlv::Append<MeshCoP::ActiveTimestampTlv>(*message, timestamp));
         }
         SuccessOrQuit(Tlv::AppendTlv(*message, MeshCoP::Tlv::kChannelMask, kChannelMask, sizeof(kChannelMask)));
@@ -645,8 +645,8 @@ void RunTest9_2_4(Topology aTopology, const char *aJsonFile)
         SuccessOrQuit(Tlv::Append<MeshCoP::CommissionerSessionIdTlv>(*message, sessionId));
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kActiveTimestampStep12);
-            timestamp.SetTicks(0);
             SuccessOrQuit(Tlv::Append<MeshCoP::ActiveTimestampTlv>(*message, timestamp));
         }
         SuccessOrQuit(Tlv::AppendTlv(*message, MeshCoP::Tlv::kChannelMask, kChannelMask, sizeof(kChannelMask)));
@@ -707,8 +707,8 @@ void RunTest9_2_4(Topology aTopology, const char *aJsonFile)
         SuccessOrQuit(Tlv::Append<MeshCoP::CommissionerSessionIdTlv>(*message, kInvalidSessionId));
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kActiveTimestampStep14);
-            timestamp.SetTicks(0);
             SuccessOrQuit(Tlv::Append<MeshCoP::ActiveTimestampTlv>(*message, timestamp));
         }
         SuccessOrQuit(Tlv::AppendTlv(*message, MeshCoP::Tlv::kChannelMask, kChannelMask, sizeof(kChannelMask)));
@@ -768,8 +768,8 @@ void RunTest9_2_4(Topology aTopology, const char *aJsonFile)
         SuccessOrQuit(Tlv::Append<MeshCoP::CommissionerSessionIdTlv>(*message, sessionId));
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kActiveTimestampStep2);
-            timestamp.SetTicks(0);
             SuccessOrQuit(Tlv::Append<MeshCoP::ActiveTimestampTlv>(*message, timestamp));
         }
         SuccessOrQuit(Tlv::AppendTlv(*message, MeshCoP::Tlv::kChannelMask, kChannelMask, sizeof(kChannelMask)));
@@ -830,8 +830,8 @@ void RunTest9_2_4(Topology aTopology, const char *aJsonFile)
         SuccessOrQuit(Tlv::Append<MeshCoP::CommissionerSessionIdTlv>(*message, sessionId));
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kActiveTimestampStep18);
-            timestamp.SetTicks(0);
             SuccessOrQuit(Tlv::Append<MeshCoP::ActiveTimestampTlv>(*message, timestamp));
         }
         SuccessOrQuit(Tlv::AppendTlv(*message, MeshCoP::Tlv::kChannelMask, kChannelMask, sizeof(kChannelMask)));
@@ -894,8 +894,8 @@ void RunTest9_2_4(Topology aTopology, const char *aJsonFile)
         SuccessOrQuit(Tlv::Append<MeshCoP::CommissionerSessionIdTlv>(*message, sessionId));
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kActiveTimestampStep20);
-            timestamp.SetTicks(0);
             SuccessOrQuit(Tlv::Append<MeshCoP::ActiveTimestampTlv>(*message, timestamp));
         }
         SuccessOrQuit(Tlv::AppendTlv(*message, MeshCoP::Tlv::kChannelMask, kChannelMask, sizeof(kChannelMask)));
diff --git a/tests/nexus/test_1_1_9_2_5.cpp b/tests/nexus/test_1_1_9_2_5.cpp
index 2fe73b273..5c27cc0e5 100644
--- a/tests/nexus/test_1_1_9_2_5.cpp
+++ b/tests/nexus/test_1_1_9_2_5.cpp
@@ -165,8 +165,8 @@ void Test9_2_5(void)
 
     SuccessOrQuit(router1.Get<MeshCoP::ActiveDatasetManager>().Read(datasetInfo));
 
+    timestamp.Clear();
     timestamp.SetSeconds(kActiveTimestampStep2);
-    timestamp.SetTicks(0);
     datasetInfo.Set<MeshCoP::Dataset::kActiveTimestamp>(timestamp);
     datasetInfo.Set<MeshCoP::Dataset::kChannelMask>(kChannelMaskStep2);
     datasetInfo.Set<MeshCoP::Dataset::kExtendedPanId>(
diff --git a/tests/nexus/test_1_1_9_2_6.cpp b/tests/nexus/test_1_1_9_2_6.cpp
index 495e438ec..9fc7ef03b 100644
--- a/tests/nexus/test_1_1_9_2_6.cpp
+++ b/tests/nexus/test_1_1_9_2_6.cpp
@@ -300,6 +300,7 @@ void Test9_2_6(void)
         SuccessOrQuit(Tlv::Append<MeshCoP::CommissionerSessionIdTlv>(*message, sessionId));
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kActiveTimestampNew);
             SuccessOrQuit(Tlv::Append<MeshCoP::ActiveTimestampTlv>(*message, timestamp));
         }
@@ -501,11 +502,13 @@ void Test9_2_6(void)
         SuccessOrQuit(Tlv::Append<MeshCoP::CommissionerSessionIdTlv>(*message, sessionId));
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kActiveTimestampFinal);
             SuccessOrQuit(Tlv::Append<MeshCoP::ActiveTimestampTlv>(*message, timestamp));
         }
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kPendingTimestamp);
             SuccessOrQuit(Tlv::Append<MeshCoP::PendingTimestampTlv>(*message, timestamp));
         }
diff --git a/tests/nexus/test_1_1_9_2_7.cpp b/tests/nexus/test_1_1_9_2_7.cpp
index 48de20698..ec0194ca4 100644
--- a/tests/nexus/test_1_1_9_2_7.cpp
+++ b/tests/nexus/test_1_1_9_2_7.cpp
@@ -280,9 +280,9 @@ void Test9_2_7(void)
 
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             // Deviation from spec: Step 5 uses 15 instead of 20 to ensure it is older than the timestamp in Step 11.
             timestamp.SetSeconds(kActiveTimestampStep5);
-            timestamp.SetTicks(0);
             datasetInfo.Set<MeshCoP::Dataset::kActiveTimestamp>(timestamp);
         }
 
@@ -397,6 +397,7 @@ void Test9_2_7(void)
         Coap::Message     *message;
         MeshCoP::Dataset   dataset;
         MeshCoP::Timestamp timestamp;
+        timestamp.Clear();
 
         message = agent.NewPriorityConfirmablePostMessage(ot::kUriPendingSet);
         VerifyOrQuit(message != nullptr);
@@ -404,11 +405,9 @@ void Test9_2_7(void)
         SuccessOrQuit(router.Get<MeshCoP::ActiveDatasetManager>().Read(dataset));
 
         timestamp.SetSeconds(kActiveTimestampRouter);
-        timestamp.SetTicks(0);
         SuccessOrQuit(dataset.Write<MeshCoP::ActiveTimestampTlv>(timestamp));
 
         timestamp.SetSeconds(kPendingTimestampRouter);
-        timestamp.SetTicks(0);
         SuccessOrQuit(dataset.Write<MeshCoP::PendingTimestampTlv>(timestamp));
 
         SuccessOrQuit(dataset.Write<MeshCoP::DelayTimerTlv>(kDelayTimerStep11 * 1000));
@@ -532,14 +531,14 @@ void Test9_2_7(void)
         SuccessOrQuit(Tlv::Append<MeshCoP::CommissionerSessionIdTlv>(*message, sessionId));
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kPendingTimestampCommissioner);
-            timestamp.SetTicks(0);
             SuccessOrQuit(Tlv::Append<MeshCoP::PendingTimestampTlv>(*message, timestamp));
         }
         {
             MeshCoP::Timestamp timestamp;
+            timestamp.Clear();
             timestamp.SetSeconds(kActiveTimestampCommissioner);
-            timestamp.SetTicks(0);
             SuccessOrQuit(Tlv::Append<MeshCoP::ActiveTimestampTlv>(*message, timestamp));
         }
         SuccessOrQuit(Tlv::Append<MeshCoP::DelayTimerTlv>(*message, kDelayTimerStep17 * 1000));