diff --git a/bmc_state_manager.hpp b/bmc_state_manager.hpp
index d50d4f3..7ffa67b 100644
--- a/bmc_state_manager.hpp
+++ b/bmc_state_manager.hpp
@@ -43,23 +43,35 @@
             sdbusRule::type::signal() + sdbusRule::member("JobRemoved") +
                 sdbusRule::path("/org/freedesktop/systemd1") +
                 sdbusRule::interface("org.freedesktop.systemd1.Manager"),
-            [this](sdbusplus::message_t& m) { bmcStateChange(m); }))
+            [this](sdbusplus::message_t& m) { bmcStateChange(m); })),
+
+        timeSyncSignal(std::make_unique<decltype(timeSyncSignal)::element_type>(
+            bus,
+            sdbusRule::propertiesChanged(
+                "/org/freedesktop/systemd1/unit/time_2dsync_2etarget",
+                "org.freedesktop.systemd1.Unit"),
+            [this](sdbusplus::message_t& m) {
+        std::string interface;
+        std::unordered_map<std::string, std::variant<std::string>>
+            propertyChanged;
+        m.read(interface, propertyChanged);
+
+        for (const auto& [key, value] : propertyChanged)
+        {
+            if (key == "ActiveState" &&
+                std::holds_alternative<std::string>(value) &&
+                std::get<std::string>(value) == "active")
+            {
+                updateLastRebootTime();
+                timeSyncSignal.reset();
+            }
+        }
+            }))
     {
         utils::subscribeToSystemdSignals(bus);
         discoverInitialState();
         discoverLastRebootCause();
-
-        using namespace std::chrono;
-        struct sysinfo info;
-
-        auto rc = sysinfo(&info);
-        assert(rc == 0);
-        // Since uptime is in seconds, also get the current time in seconds.
-        auto now = time_point_cast<seconds>(system_clock::now());
-        auto rebootTimeTs = now - seconds(info.uptime);
-        rebootTime =
-            duration_cast<milliseconds>(rebootTimeTs.time_since_epoch())
-                .count();
+        updateLastRebootTime();
 
         this->emit_object_added();
     };
@@ -115,12 +127,20 @@
     /** @brief Used to subscribe to dbus system state changes **/
     std::unique_ptr<sdbusplus::bus::match_t> stateSignal;
 
+    /** @brief Used to subscribe to timesync **/
+    std::unique_ptr<sdbusplus::bus::match_t> timeSyncSignal;
+
     /**
      * @brief discover the last reboot cause of the bmc
      **/
     void discoverLastRebootCause();
 
     /**
+     * @brief update the last reboot time of the bmc
+     **/
+    void updateLastRebootTime();
+
+    /**
      * @brief the lastRebootTime calcuated at startup.
      **/
     uint64_t rebootTime;