diff --git a/Redfish.md b/Redfish.md
index ba58c55..3739581 100644
--- a/Redfish.md
+++ b/Redfish.md
@@ -404,6 +404,7 @@
 - Links/ManagerForServers
 - Links/ManagerForServers@odata.count
 - Links/ManagerInChassis
+- Links/ServiceRootUptime
 - Links/SoftwareImages
 - Links/SoftwareImages@odata.count
 - LogServices
diff --git a/redfish-core/lib/managers.hpp b/redfish-core/lib/managers.hpp
index 376f70c..0be1354 100644
--- a/redfish-core/lib/managers.hpp
+++ b/redfish-core/lib/managers.hpp
@@ -33,6 +33,7 @@
 
 #include <algorithm>
 #include <array>
+#include <chrono>
 #include <cstdint>
 #include <memory>
 #include <sstream>
@@ -1769,6 +1770,47 @@
         });
 }
 
+inline void
+    afterGetManagerStartTime(const std::shared_ptr<bmcweb::AsyncResp>& aResp,
+                             const boost::system::error_code& ec,
+                             uint64_t bmcwebResetTime)
+{
+    if (ec)
+    {
+        return;
+    }
+    using std::chrono::steady_clock;
+    std::chrono::microseconds usReset{bmcwebResetTime};
+    steady_clock::time_point resetTime{usReset};
+
+    steady_clock::time_point now = steady_clock::now();
+
+    steady_clock::duration run = now - resetTime;
+
+    if (run < steady_clock::duration::zero())
+    {
+        BMCWEB_LOG_CRITICAL << "Uptime was negative????";
+        messages::internalError(aResp->res);
+        return;
+    }
+
+    using Milli = std::chrono::milliseconds;
+    Milli uptimeMs = std::chrono::duration_cast<Milli>(run);
+
+    using redfish::time_utils::toDurationString;
+    aResp->res.jsonValue["ServiceRootUptime"] = toDurationString(uptimeMs);
+}
+
+inline void
+    managerGetServiceRootUptime(const std::shared_ptr<bmcweb::AsyncResp>& aResp)
+{
+    sdbusplus::asio::getProperty<uint64_t>(
+        *crow::connections::systemBus, "org.freedesktop.systemd1",
+        "/org/freedesktop/systemd1/unit/bmcweb_2eservice",
+        "org.freedesktop.systemd1.Unit", "ActiveEnterTimestampMonotonic",
+        std::bind_front(afterGetManagerStartTime, aResp));
+}
+
 /**
  * @brief Set the running firmware image
  *
@@ -2026,6 +2068,8 @@
 
         managerGetLastResetTime(asyncResp);
 
+        managerGetServiceRootUptime(asyncResp);
+
         // ManagerDiagnosticData is added for all BMCs.
         nlohmann::json& managerDiagnosticData =
             asyncResp->res.jsonValue["ManagerDiagnosticData"];