diff --git a/src/libty/class_teensy.c b/src/libty/class_teensy.c
index 0e6952a..59bf147 100644
--- a/src/libty/class_teensy.c
+++ b/src/libty/class_teensy.c
@@ -133,9 +133,6 @@ static int teensy_load_interface(ty_board_interface *iface)
                         iface->capabilities |= 1 << TY_BOARD_CAPABILITY_UPLOAD;
                         iface->capabilities |= 1 << TY_BOARD_CAPABILITY_RESET;
                     }
-                    if (iface->model == TY_MODEL_TEENSY_40 || iface->model == TY_MODEL_TEENSY_41 ||
-                            iface->model == TY_MODEL_TEENSY_MM)
-                        iface->capabilities |= 1 << TY_BOARD_CAPABILITY_RTC;
                 } break;
 
                 case TEENSY_USAGE_PAGE_RAWHID: {
@@ -163,6 +160,10 @@ static int teensy_load_interface(ty_board_interface *iface)
             iface->model = TY_MODEL_TEENSY;
     }
 
+    if (iface->model == TY_MODEL_TEENSY_40 || iface->model == TY_MODEL_TEENSY_41 ||
+            iface->model == TY_MODEL_TEENSY_MM)
+        iface->capabilities |= 1 << TY_BOARD_CAPABILITY_RTC;
+
     iface->class_vtable = &_ty_teensy_class_vtable;
 
     return 1;
diff --git a/src/tycommander/board.cc b/src/tycommander/board.cc
index 8bc5dfe..391626b 100644
--- a/src/tycommander/board.cc
+++ b/src/tycommander/board.cc
@@ -102,6 +102,11 @@ void Board::loadSettings(Monitor *monitor)
         "serialLogSize",
         static_cast<quint64>(monitor ? monitor->serialLogSize() : 0)).toULongLong();
     serial_rate_ = db_.get("serialRate", 115200).toUInt();
+    {
+        int mode = db_.get("rtcMode", 0).toInt();
+        if (mode >= 0 && mode <= (int)RTC_IGNORE)
+            rtc_mode_ = (RtcMode)mode;
+    }
 
     /* Even if the user decides to enable persistence for ambiguous identifiers,
        we still don't want to cache the board model. */
@@ -304,7 +309,16 @@ TaskInterface Board::upload(const QString &filename)
 
 TaskInterface Board::upload(const vector<shared_ptr<Firmware>> &fws)
 {
-    return upload(fws, reset_after_ ? 0 : TY_UPLOAD_NORESET);
+    int flags = 0;
+
+    flags |= reset_after_ ? 0 : TY_UPLOAD_NORESET;
+    switch (rtc_mode_) {
+    case RTC_LOCALTIME: {} break;
+    case RTC_UTC: { flags |= TY_UPLOAD_RTC_UTC; } break;
+    case RTC_IGNORE: { flags |= TY_UPLOAD_NORTC; } break;
+    }
+
+    return upload(fws, flags);
 }
 
 TaskInterface Board::upload(const vector<shared_ptr<Firmware>> &fws, int flags)
@@ -533,6 +547,17 @@ void Board::setSerialLogSize(size_t size)
     emit settingsChanged();
 }
 
+void Board::setRtcMode(RtcMode mode)
+{
+    if (mode == rtc_mode_)
+        return;
+
+    rtc_mode_ = mode;
+
+    db_.put("rtcMode", static_cast<int>(mode));
+    emit settingsChanged();
+}
+
 TaskInterface Board::startUpload(const QString &filename)
 {
     auto task = upload(filename);
diff --git a/src/tycommander/board.hpp b/src/tycommander/board.hpp
index e90896c..2ed12af 100644
--- a/src/tycommander/board.hpp
+++ b/src/tycommander/board.hpp
@@ -42,6 +42,12 @@ struct BoardInterfaceInfo {
     bool open;
 };
 
+enum RtcMode {
+    RTC_LOCALTIME,
+    RTC_UTC,
+    RTC_IGNORE
+};
+
 class Board : public QObject, public std::enable_shared_from_this<Board> {
     Q_OBJECT
 
@@ -71,6 +77,7 @@ class Board : public QObject, public std::enable_shared_from_this<Board> {
     bool enable_serial_;
     QString serial_log_dir_;
     size_t serial_log_size_;
+    RtcMode rtc_mode_;
 
     QString status_text_;
     QString status_icon_name_;
@@ -127,6 +134,7 @@ class Board : public QObject, public std::enable_shared_from_this<Board> {
     bool enableSerial() const { return enable_serial_; }
     size_t serialLogSize() const { return serial_log_size_; }
     QString serialLogFilename() const { return serial_log_file_.fileName(); }
+    RtcMode rtcMode() const { return rtc_mode_; }
 
     bool serialOpen() const { return serial_iface_; }
     bool serialIsSerial() const;
@@ -161,6 +169,7 @@ public slots:
     void setScrollBackLimit(unsigned int limit);
     void setEnableSerial(bool enable, bool persist = true);
     void setSerialLogSize(size_t size);
+    void setRtcMode(RtcMode mode);
 
     TaskInterface startUpload(const QString &filename = QString());
     TaskInterface startUpload(const std::vector<std::shared_ptr<Firmware>> &fws);
diff --git a/src/tycommander/main.cc b/src/tycommander/main.cc
index 04dbd53..e59b599 100644
--- a/src/tycommander/main.cc
+++ b/src/tycommander/main.cc
@@ -22,6 +22,7 @@
 #include "../libhs/common.h"
 #include "../libty/class.h"
 #include "tycommander.hpp"
+#include "board.hpp"
 
 #ifdef QT_STATIC
     #include <QtPlugin>
@@ -141,6 +142,7 @@ int main(int argc, char *argv[])
     qRegisterMetaType<ty_descriptor>("ty_descriptor");
     qRegisterMetaType<SessionPeer::CloseReason>("SessionPeer::CloseReason");
     qRegisterMetaType<uint64_t>("uint64_t");
+    qRegisterMetaType<RtcMode>("RtcMode");
 
     QGuiApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
 
diff --git a/src/tycommander/main_window.cc b/src/tycommander/main_window.cc
index 74632d7..4308c4c 100644
--- a/src/tycommander/main_window.cc
+++ b/src/tycommander/main_window.cc
@@ -972,6 +972,10 @@ void MainWindow::refreshSettings()
 
     firmwarePath->setText(current_board_->firmware());
     resetAfterCheck->setChecked(current_board_->resetAfter());
+    rtcLayout->setEnabled(current_board_->hasCapability(TY_BOARD_CAPABILITY_RTC));
+    rtcComboBox->blockSignals(true);
+    rtcComboBox->setCurrentIndex((int)current_board_->rtcMode());
+    rtcComboBox->blockSignals(false);
     rateComboBox->blockSignals(true);
     rateComboBox->setCurrentText(QString::number(current_board_->serialRate()));
     rateComboBox->blockSignals(false);
diff --git a/src/tycommander/main_window.ui b/src/tycommander/main_window.ui
index 7141f76..790e9c3 100644
--- a/src/tycommander/main_window.ui
+++ b/src/tycommander/main_window.ui
@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>558</width>
-    <height>468</height>
+    <height>492</height>
    </rect>
   </property>
   <property name="contextMenuPolicy">
@@ -328,6 +328,49 @@
               </property>
              </widget>
             </item>
+            <item>
+             <layout class="QHBoxLayout" name="rtcLayout">
+              <item>
+               <widget class="QLabel" name="label_13">
+                <property name="text">
+                 <string>RTC:</string>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <spacer name="horizontalSpacer_6">
+                <property name="orientation">
+                 <enum>Qt::Horizontal</enum>
+                </property>
+                <property name="sizeHint" stdset="0">
+                 <size>
+                  <width>40</width>
+                  <height>20</height>
+                 </size>
+                </property>
+               </spacer>
+              </item>
+              <item>
+               <widget class="QComboBox" name="rtcComboBox">
+                <item>
+                 <property name="text">
+                  <string>Local time</string>
+                 </property>
+                </item>
+                <item>
+                 <property name="text">
+                  <string>UTC</string>
+                 </property>
+                </item>
+                <item>
+                 <property name="text">
+                  <string>Ignore RTC</string>
+                 </property>
+                </item>
+               </widget>
+              </item>
+             </layout>
+            </item>
            </layout>
           </widget>
          </item>