diff --git a/part2_architecture/lab1-2_rtc/main/main.c b/part2_architecture/lab1-2_rtc/main/main.c
index 3c13be8..4699bb0 100644
--- a/part2_architecture/lab1-2_rtc/main/main.c
+++ b/part2_architecture/lab1-2_rtc/main/main.c
@@ -6,64 +6,133 @@
  ****************************************************************************/
 
 /**
- * @file lab2-1_main.c
+ * @file lab1-2-1_main.c
  * @author Fabrice Muller
  * @date 12 Sep. 2020
- * @brief File containing the lab2-1 of Part 2.
+ * @brief File containing the lab1-2 of Part 2.
  *
  * @see https://github.com/fmuller-pns/esp32-vscode-project-template
  */
  
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
+
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
 #include "esp_system.h"
 #include "esp_spi_flash.h"
 #include "esp32/clk.h"
-#include "soc/cpu.h"
-#include "esp_heap_caps.h"
 #include "esp_log.h"
 
+#include "sys/time.h"
+#include "soc/rtc.h"
+#include "soc/cpu.h"
+
+static const char* TAG = "SYSTIME";
+
 /**
  * @brief Starting point function
  * 
  */
 
-void app_main(void) {
-    /* Print chip information */
+void app_main(void)
+{
+    /* Print RTC information */
     esp_chip_info_t chip_info;
     esp_chip_info(&chip_info);
 
-    printf("=== FLASH Memory ===\n");
+    printf("RTC clock frequency : %f KHz\n", (float)(rtc_clk_slow_freq_get_hz()/1000.0F));
 
-    int sizeOfFlash = spi_flash_get_chip_size() / (1024 * 1024);
-    if (chip_info.features & CHIP_FEATURE_EMB_FLASH)
-        printf(" - Embedded Flash (%d MiB)\n", sizeOfFlash);
-    else
-        printf(" - External Flash (%d MiB)\n", sizeOfFlash);
+    /***********************************************/
+    /* System time - gettimeofday() function       */
+    printf("\nSYSTEM DATE/TIME\n");
 
-    printf("=== DRAM/IRAM Memory ===\n");
+    struct timeval tv1,tv2,tv3,tv4 = {0};
 
-    int size = heap_caps_get_free_size(MALLOC_CAP_EXEC);
-    printf("DRAM run executable code = %d Bytes (%d KiB)\n", size, size/1024);
+    if (gettimeofday(&tv1, NULL) != 0) {
+        ESP_LOGE(TAG, "gettimeofday() failed!");
+        return;
+    }
+    ets_delay_us(1000);
+    gettimeofday(&tv2, NULL);
+    ets_delay_us(10000);
+    gettimeofday(&tv3, NULL);
+    struct timeval tv = {.tv_sec = 197130, .tv_usec=0};  
+    struct timezone utc = {0,0};
+    settimeofday(&tv, &utc);
+    gettimeofday(&tv4, NULL);
 
-    size = heap_caps_get_free_size(MALLOC_CAP_32BIT);
-    printf("DRAM run executable code 32 bit = %d Bytes (%d KiB)\n", size, size/1024);
+    /* Display times and diff time */
+	// TO DO
+	printf("Tv 1 : %ld  sec  and Tv1 %ld usec\n", tv1.tv_sec, tv1.tv_usec);
+    printf("Tv 1 : %ld  sec  and Tv2 %ld usec\n", tv1.tv_sec, tv2.tv_usec);
+    printf("Tv 1 : %ld  sec  and Tv3 %ld usec\n", tv1.tv_sec, tv3.tv_usec);
+    printf("Tv 1 : %ld  sec  and Tv4 %ld usec\n", tv1.tv_sec, tv4.tv_usec);
 
-    /* Free Heap size */
-    int DRam = heap_caps_get_free_size(MALLOC_CAP_8BIT);
-    int IRam = heap_caps_get_free_size(MALLOC_CAP_32BIT) - heap_caps_get_free_size(MALLOC_CAP_8BIT);
-    int DRAMLargestFreeBlock = heap_caps_get_largest_free_block(MALLOC_CAP_8BIT);
-    printf("IRAM = %d bytes (%d KiB)\n", IRam, IRam/1024);
-    printf("DRAM (Total) = %d Bytes (%d KiB)\n", DRam, DRam/1024);
 
-    size = xPortGetFreeHeapSize();
-    printf("DRAM Free Heap Size : %d Bytes (%d KiB)\n", size, size/1024);
+    /***********************************************/
+    /* System time - time.h library                */
+	
+	static const char* DATE_TIME_FORMAT = "%a %d %b %Y %H:%M:%S %Z";
+
+    /* Get Current time (first solution) */
+    time_t now = 0;
+    time(&now);
+
+    /* Display date/time (first solution) */
+    struct tm timeinfo = {0};
+    localtime_r(&now, &timeinfo);
+    printf("The local date and time is: %s\n", asctime(&timeinfo));
+
+    /* Waiting for 6 seconds */
+    printf("Waiting for 6 seconds ...\n");
+    usleep(6000000);
+
+    /* Get Current time (second solution) */
+    now = time(NULL);
+
+    /* Display date/time (second solution) */
+    localtime_r(&now, &timeinfo);
+    char strftime_buf[32];
+    strftime(strftime_buf, sizeof(strftime_buf), DATE_TIME_FORMAT, &timeinfo);
+    printf("SYSTEM date/time: %s\n", strftime_buf);
+
+    /* Set New Date/Time */
+    timeinfo.tm_year = 2020 - 1900; /* Year - 1900.         */ 
+    timeinfo.tm_mon = 9 - 1;        /* Month.   [0-11]      */
+    timeinfo.tm_mday = 19;          /* Day.     [1-31]      */
+    timeinfo.tm_hour = 9;           /* Hours.   [0-23]      */
+    timeinfo.tm_min = 12;           /* Minutes. [0-59]      */
+    timeinfo.tm_sec = 29;           /* Seconds. [0-60]      */
+    timeinfo.tm_isdst = 0;          /* DST. (Daylight saving time)    [-1/0/1]    */
+    time_t newTime = mktime(&timeinfo);
+     if(newTime == -1 ) {
+        ESP_LOGE(TAG, "Unable to make time using mktime()\n");
+        return;
+    } 
+    struct timeval tv_now = {.tv_sec = newTime, .tv_usec=0};
+    struct timezone utc_now = {0,0};
+    settimeofday(&tv_now, &utc_now);
+
+    /* Get Current time (first solution) and display it (first solution) */
+    time(&now);
+    localtime_r(&now, &timeinfo);
+    printf("The NEW local date and time is: %s\n", asctime(&timeinfo));
+
+    /* Waiting for 10 seconds */
+    usleep(10000000);
+
+    /* Get Current time (first solution) and display it (first solution) */
+    time(&now);
+    localtime_r(&now, &timeinfo);
+    printf("The local date and time is: %s\n", asctime(&timeinfo));
+
+    /* Using gettimeofday() function */
+    gettimeofday(&tv_now, NULL);
+    printf("tv_sec: %ld sec., tv_usec: %ld us\n", (long)tv_now.tv_sec, (long)tv_now.tv_usec);
 
-    printf("DRAM (Largest free block) = %d Bytes (%d KiB)\n", DRAMLargestFreeBlock, DRAMLargestFreeBlock/1024);
-    
 
 }
 
-