diff --git a/config.c b/config.c
index 46a33f5..aad933a 100644
--- a/config.c
+++ b/config.c
@@ -338,6 +338,7 @@ void MinimigReset()
 	spi_osd_cmd8(OSD_CMD_RST, 0x01);
 	IDE_setup();
 	spi_osd_cmd8(OSD_CMD_RST, 0x00);
+	user_io_rtc_reset();
 }
 
 //// ApplyConfiguration() ////
diff --git a/user_io.c b/user_io.c
index 6fc8396..ced19d1 100644
--- a/user_io.c
+++ b/user_io.c
@@ -4,6 +4,7 @@
 #include <inttypes.h>
 #include <stdbool.h> 
 #include <fcntl.h>
+#include <time.h>
 
 #include "hardware.h"
 #include "osd.h"
@@ -831,6 +832,12 @@ void mouse_reply(char code)
 }
 
 static uint8_t use_ps2ctl = 0;
+static unsigned long rtc_timer = 0;
+
+void user_io_rtc_reset()
+{
+	rtc_timer = 0;
+}
 
 void user_io_poll()
 {
@@ -918,6 +925,35 @@ void user_io_poll()
 				mouse_flags = 0;
 			}
 		}
+
+		if (!rtc_timer || CheckTimer(rtc_timer))
+		{
+			printf("Update RTC\n");
+
+			// Update once per minute should be enough
+			rtc_timer = GetTimer(60000);
+
+			time_t t = time(NULL);
+			struct tm tm = *localtime(&t);
+
+			uint8_t rtc[8];
+			rtc[0] = (tm.tm_sec % 10)  | ((tm.tm_sec  / 10)<<4);
+			rtc[1] = (tm.tm_min % 10)  | ((tm.tm_min  / 10)<<4);
+			rtc[2] = (tm.tm_hour % 10) | ((tm.tm_hour / 10)<<4);
+			rtc[3] = (tm.tm_mday % 10) | ((tm.tm_mday / 10)<<4);
+
+			rtc[4] = ((tm.tm_mon+1) % 10) | (((tm.tm_mon+1) / 10) << 4);
+			rtc[5] = (tm.tm_year % 10) | (((tm.tm_year / 10) % 10) << 4);
+			rtc[6] = tm.tm_wday;
+			rtc[7] = 0x40;
+
+			spi_uio_cmd_cont(UIO_RTC);
+			spi_w((rtc[1] << 8) | rtc[0]);
+			spi_w((rtc[3] << 8) | rtc[2]);
+			spi_w((rtc[5] << 8) | rtc[4]);
+			spi_w((rtc[7] << 8) | rtc[6]);
+			DisableIO();
+		}
 	}
 
 	if (core_type == CORE_TYPE_MIST)
diff --git a/user_io.h b/user_io.h
index ef38875..f003135 100644
--- a/user_io.h
+++ b/user_io.h
@@ -54,6 +54,7 @@
 #define UIO_GET_KBD_LED 0x1f  // keyboard LEDs control
 #define UIO_SET_VIDEO   0x20  // set HDMI video mode 0: 1280x720p60(TV), 1: 1280x1024p60(PC), 2-255: reserved
 #define UIO_PS2_CTL     0x21  // get PS2 control from supported cores
+#define UIO_RTC         0x22  // transmit RTC data to core
 
 // codes as used by 8bit (atari 800, zx81) via SS2
 #define UIO_GET_STATUS  0x50
@@ -200,4 +201,6 @@ unsigned char user_io_ext_idx(char *, char*);
 
 void user_io_check_reset(unsigned short modifiers, char useKeys);
 
+void user_io_rtc_reset();
+
 #endif // USER_IO_H