diff --git a/src/gridcoin/upgrade.cpp b/src/gridcoin/upgrade.cpp
index 2cb1170637..680bf77381 100644
--- a/src/gridcoin/upgrade.cpp
+++ b/src/gridcoin/upgrade.cpp
@@ -220,7 +220,7 @@ void Upgrade::SnapshotMain()
             std::cout << progress.Status() << std::flush;
         }
 
-        MilliSleep(1000);
+        UninterruptibleSleep(std::chrono::milliseconds{1000});
     }
 
     // This is needed in some spots as the download can complete before the next progress update occurs so just 100% here
@@ -248,7 +248,7 @@ void Upgrade::SnapshotMain()
             std::cout << progress.Status() << std::flush;
         }
 
-        MilliSleep(1000);
+        UninterruptibleSleep(std::chrono::milliseconds{1000});
     }
 
     if (progress.Update(100)) std::cout << progress.Status() << std::flush;
@@ -272,7 +272,7 @@ void Upgrade::SnapshotMain()
             std::cout << progress.Status() << std::flush;
         }
 
-        MilliSleep(1000);
+        UninterruptibleSleep(std::chrono::milliseconds{1000});
     }
 
     if (progress.Update(100)) std::cout << progress.Status() << std::flush;
@@ -296,7 +296,7 @@ void Upgrade::SnapshotMain()
         if (progress.Update(ExtractStatus.GetSnapshotExtractProgress()))
             std::cout << progress.Status() << std::flush;
 
-        MilliSleep(1000);
+        UninterruptibleSleep(std::chrono::milliseconds{1000});
     }
 
     if (progress.Update(100)) std::cout << progress.Status() << std::flush;
@@ -369,7 +369,7 @@ void Upgrade::WorkerMain(Progress& progress)
             }
         }
 
-        MilliSleep(1000);
+        UninterruptibleSleep(std::chrono::milliseconds{1000});
     }
 }
 
diff --git a/src/gridcoinresearchd.cpp b/src/gridcoinresearchd.cpp
index 6e53d95b3e..2a78870c4d 100644
--- a/src/gridcoinresearchd.cpp
+++ b/src/gridcoinresearchd.cpp
@@ -214,10 +214,11 @@ bool AppInit(int argc, char* argv[])
 
         PrintException(nullptr, "AppInit()");
     }
-    if(fRet)
-    {
-        while (!ShutdownRequested())
-            MilliSleep(500);
+
+    if (fRet) {
+        while (!ShutdownRequested()) {
+            UninterruptibleSleep(std::chrono::milliseconds{500});
+        }
     }
 
     Shutdown(nullptr);
diff --git a/src/init.cpp b/src/init.cpp
index c40035604d..2cc7bcd205 100755
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -37,6 +37,7 @@ extern void ThreadAppInit2(void* parg);
 using namespace std;
 CWallet* pwalletMain;
 CClientUIInterface uiInterface;
+extern std::condition_variable sleep_interrupt;
 extern bool fQtActive;
 extern bool bGridcoinCoreInitComplete;
 extern bool fConfChange;
@@ -107,13 +108,29 @@ void Shutdown(void* parg)
 
         fShutdown = true;
 
-        // clean up the threads running serviceQueue:
+        // Signal to the scheduler to stop.
+        LogPrintf("INFO: %s: Stopping the scheduler.", __func__);
+        scheduler.stop();
+
+        // clean up any remaining threads running serviceQueue:
+        LogPrintf("INFO: %s: Cleaning up any remaining threads in scheduler.", __func__);
         threadGroup.interrupt_all();
         threadGroup.join_all();
 
+        LogPrintf("INFO: %s: Flushing wallet database.", __func__);
         bitdb.Flush(false);
+
+        // Signal the sleep interrupt condition variable to interrupt sleeping threads.
+        LogPrintf("INFO: %s: Interrupting sleeping threads.", __func__);
+        sleep_interrupt.notify_all();
+
+        LogPrintf("INFO: %s: Stopping net (node) threads.", __func__);
         StopNode();
+
+        LogPrintf("INFO: %s: Final flush of wallet database and closing wallet database file.", __func__);
         bitdb.Flush(true);
+
+        LogPrintf("INFO: %s: Stopping RPC threads.", __func__);
         StopRPCThreads();
 
         // This is necessary here to prevent a snapshot download from failing at the cleanup
@@ -127,14 +144,14 @@ void Shutdown(void* parg)
         // This causes issues on daemons where it tries to create a second
         // lock file.
         //CTxDB().Close();
-        MilliSleep(50);
+        UninterruptibleSleep(std::chrono::milliseconds{50});
         LogPrintf("Gridcoin exited");
         fExit = true;
     }
     else
     {
         while (!fExit)
-            MilliSleep(100);
+            UninterruptibleSleep(std::chrono::milliseconds{100});
     }
 }
 
diff --git a/src/net.cpp b/src/net.cpp
index b347501901..081e8b62f7 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -1111,7 +1111,7 @@ void ThreadSocketHandler2(void* parg)
                 pnode->Release();
         }
 
-        MilliSleep(10);
+        UninterruptibleSleep(std::chrono::milliseconds{10});
     }
 }
 
@@ -1352,8 +1352,8 @@ void DumpAddresses()
     CAddrDB adb;
     adb.Write(addrman);
 
-    LogPrint(BCLog::LogFlags::NET, "Flushed %d addresses to peers.dat  %" PRId64 "ms",           addrman.size(), GetTimeMillis() - nStart);
-
+    LogPrint(BCLog::LogFlags::NET, "Flushed %d addresses to peers.dat  %" PRId64 "ms",
+             addrman.size(), GetTimeMillis() - nStart);
 }
 
 void ThreadDumpAddress2(void* parg)
@@ -1498,12 +1498,12 @@ void ThreadOpenConnections2(void* parg)
                 OpenNetworkConnection(addr, nullptr, strAddr.c_str());
                 for (int i = 0; i < 10 && i < nLoop; i++)
                 {
-                    MilliSleep(500);
+                    UninterruptibleSleep(std::chrono::milliseconds{500});
                     if (fShutdown)
                         return;
                 }
             }
-            MilliSleep(500);
+            UninterruptibleSleep(std::chrono::milliseconds{500});
         }
     }
 
@@ -1512,7 +1512,7 @@ void ThreadOpenConnections2(void* parg)
     while (true)
     {
         ProcessOneShot();
-        MilliSleep(500);
+        UninterruptibleSleep(std::chrono::milliseconds{500});
 
         if (fShutdown)
             return;
@@ -1638,7 +1638,7 @@ void ThreadOpenAddedConnections2(void* parg)
                 CAddress addr;
                 CSemaphoreGrant grant(*semOutbound);
                 OpenNetworkConnection(addr, &grant, strAddNode.c_str());
-                MilliSleep(500);
+                UninterruptibleSleep(std::chrono::milliseconds{500});
             }
             MilliSleep(120000); // Retry every 2 minutes
         }
@@ -1682,7 +1682,7 @@ void ThreadOpenAddedConnections2(void* parg)
         {
             CSemaphoreGrant grant(*semOutbound);
             OpenNetworkConnection(CAddress(*(vserv.begin())), &grant);
-            MilliSleep(500);
+            UninterruptibleSleep(std::chrono::milliseconds{500});
             if (fShutdown)
                 return;
         }
@@ -1817,7 +1817,7 @@ void ThreadMessageHandler2(void* parg)
 
         // Wait and allow messages to bunch up.
         // we're sleeping, but we must always check fShutdown after doing this.
-        MilliSleep(100);
+        UninterruptibleSleep(std::chrono::milliseconds{100});
         if (fRequestShutdown)
             StartShutdown();
         if (fShutdown)
@@ -2066,7 +2066,7 @@ bool StopNode()
 
     netThreads->interruptAll();
     netThreads->removeAll();
-    MilliSleep(50);
+    UninterruptibleSleep(std::chrono::milliseconds{50});
     DumpAddresses();
     return true;
 }
diff --git a/src/qt/bitcoin.cpp b/src/qt/bitcoin.cpp
index 77888c9714..dc851cada1 100755
--- a/src/qt/bitcoin.cpp
+++ b/src/qt/bitcoin.cpp
@@ -629,7 +629,7 @@ int StartGridcoinQt(int argc, char *argv[], QApplication& app, OptionsModel& opt
                 // The sleep here has to be pretty short to avoid a buffer overflow crash with
                 // fast CPUs due to too many events. It originally was set to 300 ms and has
                 // been reduced to 100 ms.
-                MilliSleep(100);
+                UninterruptibleSleep(std::chrono::milliseconds{100});
             }
 
             if (splashref)
diff --git a/src/qt/qtipcserver.cpp b/src/qt/qtipcserver.cpp
index f66d7c14a1..e9d3387f56 100644
--- a/src/qt/qtipcserver.cpp
+++ b/src/qt/qtipcserver.cpp
@@ -98,7 +98,7 @@ static void ipcThread2(void* pArg)
         if (mq->timed_receive(&buffer, sizeof(buffer), nSize, nPriority, d))
         {
             uiInterface.ThreadSafeHandleURI(std::string(buffer, nSize));
-            MilliSleep(1000);
+            UninterruptibleSleep(std::chrono::seconds{1});
         }
 
         if (fShutdown)
diff --git a/src/qt/upgradeqt.cpp b/src/qt/upgradeqt.cpp
index 5a734ed482..78ab3881ca 100644
--- a/src/qt/upgradeqt.cpp
+++ b/src/qt/upgradeqt.cpp
@@ -140,7 +140,7 @@ bool UpgradeQt::SnapshotMain(QApplication& SnapshotApp)
             }
         }
 
-        MilliSleep(poll_delay);
+        UninterruptibleSleep(std::chrono::milliseconds{poll_delay});
     }
 
     m_Progress->reset();
@@ -186,7 +186,7 @@ bool UpgradeQt::SnapshotMain(QApplication& SnapshotApp)
             }
         }
 
-        MilliSleep(poll_delay);
+        UninterruptibleSleep(std::chrono::milliseconds{poll_delay});
     }
 
     m_Progress->reset();
@@ -232,7 +232,7 @@ bool UpgradeQt::SnapshotMain(QApplication& SnapshotApp)
             }
         }
 
-        MilliSleep(poll_delay);
+        UninterruptibleSleep(std::chrono::milliseconds{poll_delay});
     }
 
     m_Progress->reset();
@@ -297,7 +297,7 @@ bool UpgradeQt::SnapshotMain(QApplication& SnapshotApp)
 
         SnapshotApp.processEvents();
 
-        MilliSleep(poll_delay);
+        UninterruptibleSleep(std::chrono::milliseconds{poll_delay});
     }
 
     m_Progress->setValue(100);
diff --git a/src/rpc/server.cpp b/src/rpc/server.cpp
index f1b78d9513..51f14d3a39 100644
--- a/src/rpc/server.cpp
+++ b/src/rpc/server.cpp
@@ -827,7 +827,7 @@ void ServiceConnection(AcceptedConnection *conn)
                If this results in a DOS the user really
                shouldn't have their RPC port exposed.*/
             if (gArgs.GetArgs("-rpcpassword").size() < 20)
-                MilliSleep(250);
+                UninterruptibleSleep(std::chrono::milliseconds{250});
 
             conn->stream() << HTTPReply(HTTP_UNAUTHORIZED, "", false) << std::flush;
             break;
diff --git a/src/util.cpp b/src/util.cpp
index d557461034..794a4547e7 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -90,7 +90,7 @@ class CInit
 
                 if (seed_successful) break;
 
-                MilliSleep(100);
+                UninterruptibleSleep(std::chrono::milliseconds{100});
             }
 
             if (!seed_successful) {
diff --git a/src/util/time.cpp b/src/util/time.cpp
index f8405f4bfb..c35e22c208 100644
--- a/src/util/time.cpp
+++ b/src/util/time.cpp
@@ -17,10 +17,26 @@
 #include <ctime>
 #include <thread>
 #include <inttypes.h>
+#include <condition_variable>
 
 #include <tinyformat.h>
 #include "logging.h"
 
+/**
+ * The global condition variable for MilliSleep, a non-Boost implementation of interruptible sleep
+ */
+std::condition_variable sleep_interrupt;
+/**
+ * The non-recursive mutex for MilliSleep, a non-Boost implementation of interruptible sleep
+ */
+std::mutex cs_interruptible_sleep;
+
+void MilliSleep(int64_t n)
+{
+    std::unique_lock<std::mutex> lock(cs_interruptible_sleep);
+    sleep_interrupt.wait_for(lock, std::chrono::milliseconds{n});
+}
+
 void UninterruptibleSleep(const std::chrono::microseconds& n) { std::this_thread::sleep_for(n); }
 
 static std::atomic<int64_t> nMockTime(0); //!< For testing
@@ -294,9 +310,3 @@ int64_t MilliTimer::GetElapsedTime(const std::string& log_string, const std::str
 
 // Create global timer instance.
 MilliTimer g_timer;
-
-void MilliSleep(int64_t n)
-{
-    std::this_thread::sleep_for(std::chrono::milliseconds(n));
-}
-
diff --git a/src/util/time.h b/src/util/time.h
index 5e86ea59a0..2cfcf56e00 100644
--- a/src/util/time.h
+++ b/src/util/time.h
@@ -17,6 +17,12 @@
 
 using namespace std::chrono_literals;
 
+/**
+ * @brief Implements an interruptible sleep using the std::mutex, std::condition_variable pattern
+ * @param int64_t n: number of milliseconds to sleep.
+ */
+void MilliSleep(int64_t n);
+
 void UninterruptibleSleep(const std::chrono::microseconds& n);
 
 /**
@@ -92,8 +98,6 @@ struct timeval MillisToTimeval(std::chrono::milliseconds ms);
 /** Sanity check epoch match normal Unix epoch */
 bool ChronoSanityCheck();
 
-void MilliSleep(int64_t n);
-
 /**
  * @brief The MilliTimer class
  *
diff --git a/src/wallet/db.cpp b/src/wallet/db.cpp
index 4a77b5aabe..00ec2462ce 100644
--- a/src/wallet/db.cpp
+++ b/src/wallet/db.cpp
@@ -441,7 +441,7 @@ bool CDB::Rewrite(const string& strFile, const char* pszSkip)
                 return fSuccess;
             }
         }
-        MilliSleep(100);
+        UninterruptibleSleep(std::chrono::milliseconds{100});
     }
     return false;
 }
diff --git a/src/wallet/walletdb.cpp b/src/wallet/walletdb.cpp
index bb6b9243a5..863960fd0b 100644
--- a/src/wallet/walletdb.cpp
+++ b/src/wallet/walletdb.cpp
@@ -638,7 +638,7 @@ void ThreadFlushWalletDB(void* parg)
     int64_t nLastWalletUpdate = GetTime();
     while (!fShutdown)
     {
-        MilliSleep(500);
+        UninterruptibleSleep(std::chrono::milliseconds{500});
 
         if (nLastSeen != nWalletDBUpdated)
         {