**SUBMODULE UPDATE - PLEASE READ!**

as of now I have added the Date library as a submodule in order to have
log messages in the correct time zone

please update your submodules by doing:
```
git submodule update --init --recursive
```

.gitmodules

@@ -22,3 +22,6 @@
 [submodule "extern/Nuked-OPL3"]
 	path = extern/Nuked-OPL3
 	url = https://github.com/nukeykt/Nuked-OPL3.git
+[submodule "extern/date"]
+	path = extern/date
+	url = https://github.com/HowardHinnant/date

CMakeLists.txt

@@ -42,6 +42,7 @@ option(SYSTEM_LIBSNDFILE "Use a system-installed version of libsndfile instead o
 option(SYSTEM_RTMIDI "Use a system-installed version of RtMidi instead of the vendored one" OFF)
 option(SYSTEM_ZLIB "Use a system-installed version of zlib instead of the vendored one" OFF)
 option(SYSTEM_SDL2 "Use a system-installed version of SDL2 instead of the vendored one" ${SYSTEM_SDL2_DEFAULT})
+option(SYSTEM_DATE "Use a system-installed version of Date instead of the vendored one" OFF)
 option(WARNINGS_ARE_ERRORS "Whether warnings in furnace's C++ code should be treated as errors" OFF)
 
 set(DEPENDENCIES_INCLUDE_DIRS "")
@@ -126,6 +127,24 @@ if (USE_RTMIDI)
   endif()
 endif()
 
+if (SYSTEM_DATE)
+  find_package(PkgConfig REQUIRED)
+  pkg_check_modules(HHDATE REQUIRED date)
+  list(APPEND DEPENDENCIES_INCLUDE_DIRS ${HHDATE_INCLUDE_DIRS})
+  list(APPEND DEPENDENCIES_COMPILE_OPTIONS ${HHDATE_CFLAGS_OTHER})
+  list(APPEND DEPENDENCIES_LIBRARIES ${HHDATE_LIBRARIES})
+  list(APPEND DEPENDENCIES_LIBRARY_DIRS ${HHDATE_LIBRARY_DIRS})
+  list(APPEND DEPENDENCIES_LINK_OPTIONS ${HHDATE_LDFLAGS_OTHER})
+  list(APPEND DEPENDENCIES_LEGACY_LDFLAGS ${HHDATE_LDFLAGS})
+  message(STATUS "Using system-installed Date")
+else()
+  set(BUILD_TZ_LIB ON CACHE BOOL "build/install of TZ library" FORCE)
+  add_subdirectory(extern/date EXCLUDE_FROM_ALL)
+  list(APPEND DEPENDENCIES_INCLUDE_DIRS extern/date/include)
+  list(APPEND DEPENDENCIES_LIBRARIES date date-tz)
+  message(STATUS "Using vendored Date")
+endif()
+
 if (SYSTEM_ZLIB)
   find_package(PkgConfig REQUIRED)
   pkg_check_modules(ZLIB REQUIRED zlib)

extern/date

@@ -0,0 +1 @@
+Subproject commit 9ea5654c1206e19245dc21d8a2c433e090c8c3f5

src/gui/gui.cpp

@@ -3439,7 +3439,8 @@ FurnaceGUI::FurnaceGUI():
   openSampleFilterOpt(false),
   oscTotal(0),
   oscZoom(0.5f),
-  oscZoomSlider(false) {
+  oscZoomSlider(false),
+  followLog(true) {
   // value keys
   valueKeys[SDLK_0]=0;
   valueKeys[SDLK_1]=1;

src/gui/gui.h

@@ -1003,6 +1003,9 @@ class FurnaceGUI {
   // visualizer
   float keyHit[DIV_MAX_CHANS];
   int lastIns[DIV_MAX_CHANS];
+  
+  // log window
+  bool followLog;
 
   void drawSSGEnv(unsigned char type, const ImVec2& size);
   void drawWaveform(unsigned char type, bool opz, const ImVec2& size);

src/gui/log.cpp

@@ -1,7 +1,7 @@
 #include "gui.h"
 #include "../ta-log.h"
 #include <chrono>
-#include <imgui.h>
+#include "date/tz.h"
 
 const char* logLevels[5]={
   "ERROR",
@@ -27,8 +27,11 @@ void FurnaceGUI::drawLog() {
   }
   if (!logOpen) return;
   if (ImGui::Begin("Log Viewer",&logOpen)) {
+    ImGui::Checkbox("Follow",&followLog);
+    ImGui::SameLine();
     ImGui::Text("Level");
     ImGui::SameLine();
+    ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
     ImGui::Combo("##LogLevel",&logLevel,logLevels,5);
     if (ImGui::BeginTable("LogView",3,ImGuiTableFlags_ScrollY|ImGuiTableFlags_BordersInnerV)) {
       ImGui::PushFont(patFont);
@@ -53,17 +56,21 @@ void FurnaceGUI::drawLog() {
         const LogEntry& logEntry=logEntries[(pos+i)&(TA_LOG_SIZE-1)];
         if (!logEntry.ready) continue;
         if (logLevel<logEntry.loglevel) continue;
-        ssize_t t=std::chrono::time_point_cast<std::chrono::seconds>(logEntry.time).time_since_epoch().count();
+        String t=date::format("%T",date::make_zoned(date::current_zone(),date::floor<std::chrono::seconds>(logEntry.time)));
         ImGui::TableNextRow();
         ImGui::TableNextColumn();
         // this will fail on 32-bit :<
-        ImGui::Text("%02ld:%02ld:%02ld",(t/3600)%24,(t/60)%60,t%60);
+        ImGui::TextUnformatted(t.c_str());
         ImGui::TableNextColumn();
         ImGui::TextColored(uiColors[logColors[logEntry.loglevel]],"%s",logLevels[logEntry.loglevel]);
         ImGui::TableNextColumn();
         ImGui::TextWrapped("%s",logEntry.text.c_str());
       }
       ImGui::PopFont();
+
+      if (followLog) {
+        ImGui::SetScrollY(ImGui::GetScrollMaxY());
+      }
       ImGui::EndTable();
     }
   }