@@ -53,6 +53,8 @@ video->nextHblankIRQ = 0;
 	video->nextVblankIRQ = 0;
 	video->nextVcounterIRQ = 0;
 
+	video->frameCounter = 0;
+
 	if (video->vram) {
 		mappedMemoryFree(video->vram, SIZE_VRAM);
 	}
@@ -115,6 +117,7 @@ if (GBARegisterDISPSTATIsVblankIRQ(video->dispstat)) {
 					GBARaiseIRQ(video->p, IRQ_VBLANK);
 				}
 				GBASyncPostFrame(video->p->sync);
+				++video->frameCounter;
 				break;
 			case VIDEO_VERTICAL_TOTAL_PIXELS - 1:
 				if (video->p->rr) {

@@ -190,6 +190,8 @@
 	uint16_t palette[SIZE_PALETTE_RAM >> 1];
 	uint16_t* vram;
 	union GBAOAM oam;
+
+	int32_t frameCounter;
 };
 
 void GBAVideoInit(struct GBAVideo* video);

@@ -8,6 +8,7 @@
 #include "AudioProcessor.h"
 #include "InputController.h"
 
+#include <QDateTime>
 #include <QThread>
 
 extern "C" {
@@ -59,10 +60,27 @@ GameControllerLux* lux = static_cast<GameControllerLux*>(context);
 		return lux->value;
 	};
 
+	m_rtc.p = this;
+	m_rtc.override = GameControllerRTC::NO_OVERRIDE;
+	m_rtc.sample = [] (GBARTCSource* context) { };
+	m_rtc.unixTime = [] (GBARTCSource* context) -> time_t {
+		GameControllerRTC* rtc = static_cast<GameControllerRTC*>(context);
+		switch (rtc->override) {
+		case GameControllerRTC::NO_OVERRIDE:
+		default:
+			return time(nullptr);
+		case GameControllerRTC::FIXED:
+			return rtc->value;
+		case GameControllerRTC::FAKE_EPOCH:
+			return rtc->value + rtc->p->m_threadContext.gba->video.frameCounter * VIDEO_TOTAL_LENGTH / GBA_ARM7TDMI_FREQUENCY;
+		}
+	};
+
 	m_threadContext.startCallback = [] (GBAThread* context) {
 		GameController* controller = static_cast<GameController*>(context->userData);
 		controller->m_audioProcessor->setInput(context);
 		context->gba->luminanceSource = &controller->m_lux;
+		context->gba->rtcSource = &controller->m_rtc;
 		controller->gameStarted(context);
 	};
 
@@ -370,6 +388,20 @@ void GameController::clearAVStream() {
 	threadInterrupt();
 	m_threadContext.stream = nullptr;
 	threadContinue();
+}
+
+void GameController::setRealTime() {
+	m_rtc.override = GameControllerRTC::NO_OVERRIDE;
+}
+
+void GameController::setFixedTime(const QDateTime& time) {
+	m_rtc.override = GameControllerRTC::FIXED;
+	m_rtc.value = time.toMSecsSinceEpoch() / 1000;
+}
+
+void GameController::setFakeEpoch(const QDateTime& time) {
+	m_rtc.override = GameControllerRTC::FAKE_EPOCH;
+	m_rtc.value = time.toMSecsSinceEpoch() / 1000;
 }
 
 void GameController::updateKeys() {

@@ -94,6 +94,10 @@ void setAVStream(GBAAVStream*);
 	void clearAVStream();
 	void setLuminanceValue(uint8_t value) { m_luxValue = value; }
 
+	void setRealTime();
+	void setFixedTime(const QDateTime& time);
+	void setFakeEpoch(const QDateTime& time);
+
 	void setLogLevel(int);
 	void enableLogLevel(int);
 	void disableLogLevel(int);
@@ -144,6 +148,16 @@ GameController* p;
 		uint8_t value;
 	} m_lux;
 	uint8_t m_luxValue;
+
+	struct GameControllerRTC : GBARTCSource {
+		GameController* p;
+		enum {
+			NO_OVERRIDE,
+			FIXED,
+			FAKE_EPOCH
+		} override;
+		int64_t value;
+	} m_rtc;
 };
 
 }

@@ -24,6 +24,17 @@ connect(controller, SIGNAL(gameStopped(GBAThread*)), this, SLOT(gameStopped()));
 	connect(m_ui.lightSpin, SIGNAL(valueChanged(int)), this, SLOT(setLuminanceValue(int)));
 	connect(m_ui.lightSlide, SIGNAL(valueChanged(int)), this, SLOT(setLuminanceValue(int)));
 
+	connect(m_ui.timeNoOverride, SIGNAL(clicked()), controller, SLOT(setRealTime()));
+	connect(m_ui.timeFixed, &QRadioButton::clicked, [controller, this] () {
+		controller->setFixedTime(m_ui.time->dateTime());
+	});
+	connect(m_ui.timeFakeEpoch, &QRadioButton::clicked, [controller, this] () {
+		controller->setFakeEpoch(m_ui.time->dateTime());
+	});
+	connect(m_ui.time, &QDateTimeEdit::dateTimeChanged, [controller, this] (const QDateTime&) {
+		m_ui.timeButtons->checkedButton()->clicked();
+	});
+
 	if (controller->isLoaded()) {
 		gameStarted(controller->thread());
 	}

@@ -151,38 +151,65 @@ <string>RTC</string>
       </attribute>
       <layout class="QVBoxLayout" name="verticalLayout">
        <item>
-        <widget class="QRadioButton" name="radioButton">
-         <property name="enabled">
-          <bool>false</bool>
-         </property>
+        <widget class="QRadioButton" name="timeNoOverride">
          <property name="text">
           <string>System time</string>
          </property>
          <property name="checked">
           <bool>true</bool>
          </property>
+         <attribute name="buttonGroup">
+          <string notr="true">timeButtons</string>
+         </attribute>
         </widget>
        </item>
        <item>
-        <widget class="QRadioButton" name="radioButton_2">
-         <property name="enabled">
-          <bool>false</bool>
+        <widget class="QRadioButton" name="timeFixed">
+         <property name="text">
+          <string>Fixed time</string>
          </property>
+         <attribute name="buttonGroup">
+          <string notr="true">timeButtons</string>
+         </attribute>
+        </widget>
+       </item>
+       <item>
+        <widget class="QRadioButton" name="timeFakeEpoch">
          <property name="text">
-          <string>Manual time</string>
+          <string>Start time at</string>
          </property>
+         <attribute name="buttonGroup">
+          <string notr="true">timeButtons</string>
+         </attribute>
         </widget>
        </item>
        <item>
-        <widget class="QDateTimeEdit" name="dateTimeEdit">
-         <property name="enabled">
-          <bool>false</bool>
+        <widget class="QDateTimeEdit" name="time">
+         <property name="wrapping">
+          <bool>true</bool>
+         </property>
+         <property name="maximumDate">
+          <date>
+           <year>2099</year>
+           <month>12</month>
+           <day>31</day>
+          </date>
+         </property>
+         <property name="minimumDate">
+          <date>
+           <year>2000</year>
+           <month>1</month>
+           <day>1</day>
+          </date>
+         </property>
+         <property name="currentSection">
+          <enum>QDateTimeEdit::MonthSection</enum>
          </property>
          <property name="displayFormat">
-          <string>M/d/yyyy h:mm AP</string>
+          <string>MM/dd/yy hh:mm:ss AP</string>
          </property>
-         <property name="calendarPopup">
-          <bool>false</bool>
+         <property name="timeSpec">
+          <enum>Qt::UTC</enum>
          </property>
         </widget>
        </item>
@@ -231,4 +258,7 @@ </layout>
  </widget>
  <resources/>
  <connections/>
+ <buttongroups>
+  <buttongroup name="timeButtons"/>
+ </buttongroups>
 </ui>