diff --git a/src/messaging/ReliableMessageContext.cpp b/src/messaging/ReliableMessageContext.cpp
index a4bdbd14e47d2e..e30447050e0fd4 100644
--- a/src/messaging/ReliableMessageContext.cpp
+++ b/src/messaging/ReliableMessageContext.cpp
@@ -257,7 +257,7 @@ CHIP_ERROR ReliableMessageContext::HandleNeedsAckInner(uint32_t messageCounter,
         SetPendingPeerAckMessageCounter(messageCounter);
         mNextAckTimeTick = static_cast<uint16_t>(
             CHIP_CONFIG_RMP_DEFAULT_ACK_TIMEOUT_TICK +
-            GetReliableMessageMgr()->GetTickCounterFromTimeDelta(System::SystemClock().GetMonotonicMilliseconds()));
+            GetReliableMessageMgr()->GetTickCounterFromTimeDelta(System::SystemClock().GetMonotonicTimestamp()));
         return CHIP_NO_ERROR;
     }
 }
diff --git a/src/messaging/ReliableMessageMgr.cpp b/src/messaging/ReliableMessageMgr.cpp
index d8663111914118..10364a543a8116 100644
--- a/src/messaging/ReliableMessageMgr.cpp
+++ b/src/messaging/ReliableMessageMgr.cpp
@@ -58,8 +58,8 @@ ReliableMessageMgr::~ReliableMessageMgr() {}
 void ReliableMessageMgr::Init(chip::System::Layer * systemLayer, SessionManager * sessionManager)
 {
     mSystemLayer        = systemLayer;
-    mTimeStampBase      = System::SystemClock().GetMonotonicMilliseconds();
-    mCurrentTimerExpiry = 0;
+    mTimeStampBase      = System::SystemClock().GetMonotonicTimestamp();
+    mCurrentTimerExpiry = System::Clock::Zero;
 }
 
 void ReliableMessageMgr::Shutdown()
@@ -75,12 +75,12 @@ void ReliableMessageMgr::Shutdown()
     mSystemLayer = nullptr;
 }
 
-uint64_t ReliableMessageMgr::GetTickCounterFromTimePeriod(uint64_t period)
+uint64_t ReliableMessageMgr::GetTickCounterFromTimePeriod(System::Clock::Milliseconds64 period)
 {
-    return (period >> mTimerIntervalShift);
+    return (period.count() >> mTimerIntervalShift);
 }
 
-uint64_t ReliableMessageMgr::GetTickCounterFromTimeDelta(uint64_t newTime)
+uint64_t ReliableMessageMgr::GetTickCounterFromTimeDelta(System::Clock::Timestamp newTime)
 {
     return GetTickCounterFromTimePeriod(newTime - mTimeStampBase);
 }
@@ -197,7 +197,7 @@ static void TickProceed(uint16_t & time, uint64_t ticks)
 
 void ReliableMessageMgr::ExpireTicks()
 {
-    uint64_t now = System::SystemClock().GetMonotonicMilliseconds();
+    System::Clock::Timestamp now = System::SystemClock().GetMonotonicTimestamp();
 
     // Number of full ticks elapsed since last timer processing.  We always round down
     // to the previous tick.  If we are between tick boundaries, the extra time since the
@@ -231,10 +231,10 @@ void ReliableMessageMgr::ExpireTicks()
     });
 
     // Re-Adjust the base time stamp to the most recent tick boundary
-    mTimeStampBase += (deltaTicks << mTimerIntervalShift);
+    mTimeStampBase += System::Clock::Milliseconds32(deltaTicks << mTimerIntervalShift);
 
 #if defined(RMP_TICKLESS_DEBUG)
-    ChipLogDetail(ExchangeManager, "ReliableMessageMgr::ExpireTicks mTimeStampBase to %" PRIu64, mTimeStampBase);
+    ChipLogDetail(ExchangeManager, "ReliableMessageMgr::ExpireTicks mTimeStampBase to %" PRIu64, mTimeStampBase.count());
 #endif
 }
 
@@ -278,9 +278,8 @@ CHIP_ERROR ReliableMessageMgr::AddToRetransTable(ReliableMessageContext * rc, Re
 
 void ReliableMessageMgr::StartRetransmision(RetransTableEntry * entry)
 {
-    entry->nextRetransTimeTick =
-        static_cast<uint16_t>(entry->ec->GetInitialRetransmitTimeoutTick() +
-                              GetTickCounterFromTimeDelta(System::SystemClock().GetMonotonicMilliseconds()));
+    entry->nextRetransTimeTick = static_cast<uint16_t>(entry->ec->GetInitialRetransmitTimeoutTick() +
+                                                       GetTickCounterFromTimeDelta(System::SystemClock().GetMonotonicTimestamp()));
 
     // Check if the timer needs to be started and start it.
     StartTimer();
@@ -437,7 +436,8 @@ void ReliableMessageMgr::StartTimer()
     if (foundWake)
     {
         // Set timer for next tick boundary - subtract the elapsed time from the current tick
-        System::Clock::MonotonicMilliseconds timerExpiry = (nextWakeTimeTick << mTimerIntervalShift) + mTimeStampBase;
+        System::Clock::Timestamp timerExpiry =
+            System::Clock::Milliseconds32(nextWakeTimeTick << mTimerIntervalShift) + mTimeStampBase;
 
 #if defined(RMP_TICKLESS_DEBUG)
         ChipLogDetail(ExchangeManager, "ReliableMessageMgr::StartTimer wake at %" PRIu64 " ms (%" PRIu64 " %" PRIu64 ")",
@@ -447,14 +447,15 @@ void ReliableMessageMgr::StartTimer()
         {
             // If the tick boundary has expired in the past (delayed processing of event due to other system activity),
             // expire the timer immediately
-            uint64_t now           = System::SystemClock().GetMonotonicMilliseconds();
-            uint64_t timerArmValue = (timerExpiry > now) ? timerExpiry - now : 0;
+            System::Clock::Timestamp now         = System::SystemClock().GetMonotonicTimestamp();
+            System::Clock::Timeout timerArmValue = (timerExpiry > now) ? timerExpiry - now : System::Clock::Zero;
 
 #if defined(RMP_TICKLESS_DEBUG)
-            ChipLogDetail(ExchangeManager, "ReliableMessageMgr::StartTimer set timer for %" PRIu64, timerArmValue);
+            ChipLogDetail(ExchangeManager, "ReliableMessageMgr::StartTimer set timer for %" PRIu32 " ms",
+                          System::Clock::Milliseconds32(timerArmValue).count());
 #endif
             StopTimer();
-            res = mSystemLayer->StartTimer(System::Clock::Milliseconds32(timerArmValue), Timeout, this);
+            res = mSystemLayer->StartTimer(timerArmValue, Timeout, this);
 
             VerifyOrDieWithMsg(res == CHIP_NO_ERROR, ExchangeManager,
                                "Cannot start ReliableMessageMgr::Timeout %" CHIP_ERROR_FORMAT, res.Format());
diff --git a/src/messaging/ReliableMessageMgr.h b/src/messaging/ReliableMessageMgr.h
index 5befa502b0b753..617007a2f81b45 100644
--- a/src/messaging/ReliableMessageMgr.h
+++ b/src/messaging/ReliableMessageMgr.h
@@ -83,7 +83,7 @@ class ReliableMessageMgr
      *
      * @return Tick count for the time period.
      */
-    uint64_t GetTickCounterFromTimePeriod(uint64_t period);
+    uint64_t GetTickCounterFromTimePeriod(System::Clock::Milliseconds64 period);
 
     /**
      * Return a tick counter value between the given time and the stored time.
@@ -92,7 +92,7 @@ class ReliableMessageMgr
      *
      * @return Tick count of the difference between the given time and the stored time.
      */
-    uint64_t GetTickCounterFromTimeDelta(uint64_t newTime);
+    uint64_t GetTickCounterFromTimeDelta(System::Clock::Timestamp newTime);
 
     /**
      * Iterate through active exchange contexts and retrans table entries.  If an
@@ -230,9 +230,9 @@ class ReliableMessageMgr
 private:
     BitMapObjectPool<ExchangeContext, CHIP_CONFIG_MAX_EXCHANGE_CONTEXTS> & mContextPool;
     chip::System::Layer * mSystemLayer;
-    uint64_t mTimeStampBase; // ReliableMessageProtocol timer base value to add offsets to evaluate timeouts
-    System::Clock::MonotonicMilliseconds mCurrentTimerExpiry; // Tracks when the ReliableMessageProtocol timer will next expire
-    uint16_t mTimerIntervalShift;                             // ReliableMessageProtocol Timer tick period shift
+    System::Clock::Timestamp mTimeStampBase;      // ReliableMessageProtocol timer base value to add offsets to evaluate timeouts
+    System::Clock::Timestamp mCurrentTimerExpiry; // Tracks when the ReliableMessageProtocol timer will next expire
+    uint16_t mTimerIntervalShift;                 // ReliableMessageProtocol Timer tick period shift
 
     /* Placeholder function to run a function for all exchanges */
     template <typename Function>
diff --git a/src/messaging/tests/echo/echo_requester.cpp b/src/messaging/tests/echo/echo_requester.cpp
index d2f87803bdb134..b8977c6133c0dd 100644
--- a/src/messaging/tests/echo/echo_requester.cpp
+++ b/src/messaging/tests/echo/echo_requester.cpp
@@ -49,8 +49,8 @@ namespace {
 // Max value for the number of EchoRequests sent.
 constexpr size_t kMaxEchoCount = 3;
 
-// The CHIP Echo interval time in milliseconds.
-constexpr int32_t gEchoInterval = 1000;
+// The CHIP Echo interval time.
+constexpr chip::System::Clock::Timeout gEchoInterval = chip::System::Clock::Seconds16(1);
 
 constexpr chip::FabricIndex gFabricIndex = 0;
 
@@ -62,7 +62,7 @@ chip::TransportMgr<chip::Transport::TCP<kMaxTcpActiveConnectionCount, kMaxTcpPen
 chip::Inet::IPAddress gDestAddr;
 
 // The last time a CHIP Echo was attempted to be sent.
-uint64_t gLastEchoTime = 0;
+chip::System::Clock::Timestamp gLastEchoTime{ 0 };
 
 // Count of the number of EchoRequests sent.
 uint64_t gEchoCount = 0;
@@ -121,9 +121,9 @@ CHIP_ERROR SendEchoRequest()
         return CHIP_ERROR_NO_MEMORY;
     }
 
-    gLastEchoTime = chip::System::SystemClock().GetMonotonicMilliseconds();
+    gLastEchoTime = chip::System::SystemClock().GetMonotonicTimestamp();
 
-    err = chip::DeviceLayer::SystemLayer().StartTimer(chip::System::Clock::Milliseconds32(gEchoInterval), EchoTimerHandler, NULL);
+    err = chip::DeviceLayer::SystemLayer().StartTimer(gEchoInterval, EchoTimerHandler, NULL);
     if (err != CHIP_NO_ERROR)
     {
         printf("Unable to schedule timer\n");
@@ -173,7 +173,7 @@ CHIP_ERROR EstablishSecureSession()
     if (err != CHIP_NO_ERROR)
     {
         printf("Establish secure session failed, err: %s\n", chip::ErrorStr(err));
-        gLastEchoTime = chip::System::SystemClock().GetMonotonicMilliseconds();
+        gLastEchoTime = chip::System::SystemClock().GetMonotonicTimestamp();
     }
     else
     {
@@ -185,13 +185,14 @@ CHIP_ERROR EstablishSecureSession()
 
 void HandleEchoResponseReceived(chip::Messaging::ExchangeContext * ec, chip::System::PacketBufferHandle && payload)
 {
-    uint32_t respTime    = chip::System::SystemClock().GetMonotonicMilliseconds();
-    uint32_t transitTime = respTime - gLastEchoTime;
+    chip::System::Clock::Timestamp respTime  = chip::System::SystemClock().GetMonotonicTimestamp();
+    chip::System::Clock::Timeout transitTime = respTime - gLastEchoTime;
 
     gEchoRespCount++;
 
-    printf("Echo Response: %" PRIu64 "/%" PRIu64 "(%.2f%%) len=%u time=%.3fms\n", gEchoRespCount, gEchoCount,
-           static_cast<double>(gEchoRespCount) * 100 / gEchoCount, payload->DataLength(), static_cast<double>(transitTime) / 1000);
+    printf("Echo Response: %" PRIu64 "/%" PRIu64 "(%.2f%%) len=%u time=%.3fs\n", gEchoRespCount, gEchoCount,
+           static_cast<double>(gEchoRespCount) * 100 / gEchoCount, payload->DataLength(),
+           static_cast<double>(chip::System::Clock::Milliseconds32(transitTime).count()) / 1000);
 }
 
 } // namespace
diff --git a/src/transport/SessionManager.cpp b/src/transport/SessionManager.cpp
index 0fccd619a16e87..3fceaa6eb6b417 100644
--- a/src/transport/SessionManager.cpp
+++ b/src/transport/SessionManager.cpp
@@ -184,7 +184,7 @@ CHIP_ERROR SessionManager::SendPreparedMessage(SessionHandle session, const Encr
                         "Sending %s msg %p with MessageCounter:" ChipLogFormatMessageCounter " to 0x" ChipLogFormatX64
                         " at monotonic time: %" PRId64 " msec",
                         "encrypted", &preparedMessage, preparedMessage.GetMessageCounter(), ChipLogValueX64(state->GetPeerNodeId()),
-                        System::SystemClock().GetMonotonicMilliseconds());
+                        System::SystemClock().GetMonotonicMilliseconds64().count());
     }
     else
     {
@@ -196,7 +196,7 @@ CHIP_ERROR SessionManager::SendPreparedMessage(SessionHandle session, const Encr
                         "Sending %s msg %p with MessageCounter:" ChipLogFormatMessageCounter " to 0x" ChipLogFormatX64
                         " at monotonic time: %" PRId64 " msec",
                         "plaintext", &preparedMessage, preparedMessage.GetMessageCounter(), ChipLogValueX64(kUndefinedNodeId),
-                        System::SystemClock().GetMonotonicMilliseconds());
+                        System::SystemClock().GetMonotonicMilliseconds64().count());
     }
 
     PacketBufferHandle msgBuf = preparedMessage.CastToWritable();
diff --git a/src/transport/raw/tests/NetworkTestHelpers.cpp b/src/transport/raw/tests/NetworkTestHelpers.cpp
index c9f150b308322b..34dcbf819adec1 100644
--- a/src/transport/raw/tests/NetworkTestHelpers.cpp
+++ b/src/transport/raw/tests/NetworkTestHelpers.cpp
@@ -60,15 +60,15 @@ void IOContext::DriveIO()
     ServiceEvents(kSleepTimeMilliseconds);
 }
 
-void IOContext::DriveIOUntil(unsigned maxWaitMs, std::function<bool(void)> completionFunction)
+void IOContext::DriveIOUntil(System::Clock::Timeout maxWait, std::function<bool(void)> completionFunction)
 {
-    uint64_t mStartTime = System::SystemClock().GetMonotonicMilliseconds();
+    System::Clock::Timestamp startTime = System::SystemClock().GetMonotonicTimestamp();
 
     while (true)
     {
         DriveIO(); // at least one IO loop is guaranteed
 
-        if (completionFunction() || ((System::SystemClock().GetMonotonicMilliseconds() - mStartTime) >= maxWaitMs))
+        if (completionFunction() || ((System::SystemClock().GetMonotonicTimestamp() - startTime) >= maxWait))
         {
             break;
         }
diff --git a/src/transport/raw/tests/NetworkTestHelpers.h b/src/transport/raw/tests/NetworkTestHelpers.h
index 361ec7d9e09357..873a6ec56a664a 100644
--- a/src/transport/raw/tests/NetworkTestHelpers.h
+++ b/src/transport/raw/tests/NetworkTestHelpers.h
@@ -48,7 +48,7 @@ class IOContext
 
     /// DriveIO until the specified number of milliseconds has passed or until
     /// completionFunction returns true
-    void DriveIOUntil(unsigned maxWaitMs, std::function<bool(void)> completionFunction);
+    void DriveIOUntil(System::Clock::Timeout maxWait, std::function<bool(void)> completionFunction);
 
     nlTestSuite * GetTestSuite() { return mSuite; }
     System::Layer & GetSystemLayer() { return *mSystemLayer; }
diff --git a/src/transport/raw/tests/TestTCP.cpp b/src/transport/raw/tests/TestTCP.cpp
index b87cf48ec0b589..98a406966d64c9 100644
--- a/src/transport/raw/tests/TestTCP.cpp
+++ b/src/transport/raw/tests/TestTCP.cpp
@@ -142,7 +142,7 @@ class MockTransportMgrDelegate : public chip::TransportMgrDelegate
 
         NL_TEST_ASSERT(mSuite, err == CHIP_NO_ERROR);
 
-        mContext.DriveIOUntil(5000 /* ms */, [this]() { return mReceiveHandlerCallCount != 0; });
+        mContext.DriveIOUntil(chip::System::Clock::Seconds16(5), [this]() { return mReceiveHandlerCallCount != 0; });
         NL_TEST_ASSERT(mSuite, mReceiveHandlerCallCount == 1);
 
         SetCallback(nullptr);
@@ -152,7 +152,7 @@ class MockTransportMgrDelegate : public chip::TransportMgrDelegate
     {
         // Disconnect and wait for seeing peer close
         tcp.Disconnect(Transport::PeerAddress::TCP(addr));
-        mContext.DriveIOUntil(5000 /* ms */, [&tcp]() { return !tcp.HasActiveConnections(); });
+        mContext.DriveIOUntil(chip::System::Clock::Seconds16(5), [&tcp]() { return !tcp.HasActiveConnections(); });
     }
 
     int mReceiveHandlerCallCount = 0;
diff --git a/src/transport/raw/tests/TestUDP.cpp b/src/transport/raw/tests/TestUDP.cpp
index dd997a21f47457..88057e6770809b 100644
--- a/src/transport/raw/tests/TestUDP.cpp
+++ b/src/transport/raw/tests/TestUDP.cpp
@@ -150,7 +150,7 @@ void CheckMessageTest(nlTestSuite * inSuite, void * inContext, const IPAddress &
 
     NL_TEST_ASSERT(inSuite, err == CHIP_NO_ERROR);
 
-    ctx.DriveIOUntil(1000 /* ms */, []() { return ReceiveHandlerCallCount != 0; });
+    ctx.DriveIOUntil(chip::System::Clock::Seconds16(1), []() { return ReceiveHandlerCallCount != 0; });
 
     NL_TEST_ASSERT(inSuite, ReceiveHandlerCallCount == 1);
 }