diff --git a/main/CMakeLists.txt b/main/CMakeLists.txt
index 7a41015..7887b6e 100644
--- a/main/CMakeLists.txt
+++ b/main/CMakeLists.txt
@@ -4,7 +4,6 @@ idf_component_register(SRCS
     "assets/fonts/bebas_neue/bebas_neue_120.c"
     "assets/fonts/material_webfont/material_webfont_32.c"
     "main.c"
-    "service/service_wifi.c"
     "impl/impl_btn.c"
     "impl/impl_dht.c"
     "impl/impl_epd.c"
@@ -166,7 +165,9 @@ idf_component_register(SRCS
     "lib/lvgl/src/widgets/lv_switch.c"
     "lib/lvgl/src/widgets/lv_table.c"
     "lib/lvgl/src/widgets/lv_textarea.c"
+    "service/service_clock.c"
     "service/service_dht.c"
+    "service/service_wifi.c"
 
 INCLUDE_DIRS
     "lib"
diff --git a/main/impl/impl_lvgl.c b/main/impl/impl_lvgl.c
index f5826bc..fe94010 100644
--- a/main/impl/impl_lvgl.c
+++ b/main/impl/impl_lvgl.c
@@ -230,7 +230,7 @@ esp_err_t impl_lvgl_init(void) {
     lv_theme_t *default_theme = lv_theme_mono_init(disp, false, &lv_font_unscii_16);
     lv_disp_set_theme(disp, default_theme);
 
-    s_lv_semphr_handle = xSemaphoreCreateBinary();
+    s_lv_semphr_handle = xSemaphoreCreateMutex();
     if (s_lv_semphr_handle == NULL) {
         ESP_LOGE(LOG_TAG, "LVGL semaphore creation failed.");
         return ESP_FAIL;
diff --git a/main/interface/if_battery.c b/main/interface/if_battery.c
new file mode 100644
index 0000000..e69de29
diff --git a/main/interface/if_battery.h b/main/interface/if_battery.h
new file mode 100644
index 0000000..e69de29
diff --git a/main/interface/if_standby.c b/main/interface/if_standby.c
index a1766b1..9381df7 100644
--- a/main/interface/if_standby.c
+++ b/main/interface/if_standby.c
@@ -159,7 +159,18 @@ void if_standby_task(void *pvParameters) {
             case IF_STANDBY_ITEM_HUMID:
                 lv_label_set_text(humid_label, queue_item.payload);
                 lv_obj_align(humid_label, LV_ALIGN_CENTER, 0, 16);
-
+                break;
+            case IF_STANDBY_ITEM_TIME:
+                lv_label_set_text(time_label, queue_item.payload);
+                lv_obj_set_align(time_label, LV_ALIGN_CENTER);
+                break;
+            case IF_STANDBY_ITEM_DATE:
+                lv_label_set_text(date_label, queue_item.payload);
+                lv_obj_set_align(date_label, LV_ALIGN_CENTER);
+                break;
+            case IF_STANDBY_ITEM_WEEKDAY:
+                lv_label_set_text(weekday_label, queue_item.payload);
+                lv_obj_set_align(weekday_label, LV_ALIGN_CENTER);
                 break;
             default:
                 break;
@@ -175,7 +186,7 @@ esp_err_t if_standby_init(void) {
     impl_lvgl_unlock();
 
     g_standby_screen_queue = xQueueCreate(8, sizeof(if_standby_queue_t));
-    if(g_standby_screen_queue == NULL) {
+    if (g_standby_screen_queue == NULL) {
         return ESP_FAIL;
     }
 
diff --git a/main/interface/if_standby.h b/main/interface/if_standby.h
index 83315a5..e3795ac 100644
--- a/main/interface/if_standby.h
+++ b/main/interface/if_standby.h
@@ -8,6 +8,8 @@
 
 #include "lvgl.h"
 
+#define IF_STANDBY_PAYLOAD_LENGTH 16
+
 typedef enum {
     IF_STANDBY_ITEM_WIFI,
     IF_STANDBY_ITEM_WEEKDAY,
@@ -20,7 +22,7 @@ typedef enum {
 
 typedef struct {
     if_standby_item_t item;
-    char payload[16];
+    char payload[IF_STANDBY_PAYLOAD_LENGTH];
 } if_standby_queue_t;
 
 extern lv_obj_t *g_standby_screen;
diff --git a/main/interface/if_wifi.c b/main/interface/if_wifi.c
index c72f3ba..0b08b7f 100644
--- a/main/interface/if_wifi.c
+++ b/main/interface/if_wifi.c
@@ -2,6 +2,11 @@
 
 #include "esp_system.h"
 
+
+void if_wifi_task(void *pvParameters) {
+    
+}
+
 /**
  * @brief Initialize WiFi status/configuration component
  * 
@@ -11,8 +16,3 @@
 esp_err_t if_wifi_init(lv_obj_t *parent_obj) {
     return ESP_OK;
 }
-
-esp_err_t if_wifi_destroy(void) {
-    //
-    return ESP_OK;
-}
\ No newline at end of file
diff --git a/main/lib/ltc2941/ltc2941.c b/main/lib/ltc2941/ltc2941.c
new file mode 100644
index 0000000..e69de29
diff --git a/main/lib/ltc2941/ltc2941.h b/main/lib/ltc2941/ltc2941.h
new file mode 100644
index 0000000..e69de29
diff --git a/main/lib/lv_conf.h b/main/lib/lv_conf.h
index 81f17ce..acfb759 100644
--- a/main/lib/lv_conf.h
+++ b/main/lib/lv_conf.h
@@ -181,7 +181,7 @@ e.g. "stm32f769xx.h" or "stm32f429xx.h"*/
  *LV_LOG_LEVEL_ERROR       Only critical issue, when the system may fail
  *LV_LOG_LEVEL_USER        Only logs added by the user
  *LV_LOG_LEVEL_NONE        Do not log anything*/
-#  define LV_LOG_LEVEL LV_LOG_LEVEL_INFO
+#  define LV_LOG_LEVEL LV_LOG_LEVEL_WARN
 
 /*1: Print the log with 'printf';
  *0: User need to register a callback with `lv_log_register_print_cb()`*/
diff --git a/main/main.c b/main/main.c
index 45b3520..2c165d6 100644
--- a/main/main.c
+++ b/main/main.c
@@ -13,6 +13,7 @@
 #include "if_standby.h"
 #include "impl_lvgl.h"
 #include "service_dht.h"
+#include "service_clock.h"
 
 #define APP_I2C_MASTER_NUM 0
 #define APP_I2C_SDA_NUM    GPIO_NUM_39
@@ -59,6 +60,7 @@ void app_main(void) {
     ESP_ERROR_CHECK(if_standby_init());
 
     ESP_ERROR_CHECK(service_dht_init());
+    ESP_ERROR_CHECK(service_clock_init());
 
     /* Dead loop */
     for (;;) {
diff --git a/main/service/service_clock.c b/main/service/service_clock.c
new file mode 100644
index 0000000..2a83fc8
--- /dev/null
+++ b/main/service/service_clock.c
@@ -0,0 +1,65 @@
+#include "service_clock.h"
+
+#include <time.h>
+
+#include "esp_log.h"
+#include "if_standby.h"
+
+#define LOG_TAG "SERVICE_CLOCK"
+
+static TaskHandle_t s_clock_task_handle;
+
+static char *s_wday_array[] = {"SUN", "MON", "TUE", "WED", "THU", "FRI"};
+
+void clock_task(void *pvParameters) {
+    struct tm timeinfo;
+    time_t    now;
+
+    uint8_t prev_min  = 0xFF;
+    uint8_t prev_mday = 0xFF;
+    uint8_t prev_wday = 0xFF;
+
+    if_standby_queue_t queue_item;
+
+    setenv("TZ", "CST-8", 1);
+    tzset();
+
+    for (;;) {
+        time(&now);
+        localtime_r(&now, &timeinfo);
+
+        if ((timeinfo.tm_min != prev_min) || (prev_min == 0xFF)) {
+            queue_item.item = IF_STANDBY_ITEM_TIME;
+            snprintf(queue_item.payload, IF_STANDBY_PAYLOAD_LENGTH, "%02u:%02u", timeinfo.tm_hour, timeinfo.tm_min);
+            xQueueSendToBack(g_standby_screen_queue, &queue_item, 0);
+
+            prev_min = timeinfo.tm_min;
+        }
+        if ((timeinfo.tm_mday != prev_mday) || (prev_mday == 0xFF)) {
+            queue_item.item = IF_STANDBY_ITEM_DATE;
+            snprintf(queue_item.payload, IF_STANDBY_PAYLOAD_LENGTH, "%04u/%02d/%02d",
+                     (uint16_t)(timeinfo.tm_year + 1900), (uint8_t)(timeinfo.tm_mon + 1), (uint8_t)timeinfo.tm_mday);
+            xQueueSendToBack(g_standby_screen_queue, &queue_item, 0);
+
+            prev_mday = timeinfo.tm_mday;
+        }
+        if ((timeinfo.tm_wday != prev_wday) || (prev_wday == 0xFF)) {
+            queue_item.item = IF_STANDBY_ITEM_WEEKDAY;
+            memcpy(queue_item.payload, s_wday_array[timeinfo.tm_wday], 4);
+            xQueueSendToBack(g_standby_screen_queue, &queue_item, 0);
+
+            prev_wday = timeinfo.tm_wday;
+        }
+
+        // TODO: Set an alarm at 0sec every 1 minute.
+        vTaskDelay(pdMS_TO_TICKS(200));
+    }
+}
+
+esp_err_t service_clock_init(void) {
+    if (xTaskCreate(clock_task, "CLOCK", 2048, NULL, 6, &s_clock_task_handle) != pdTRUE) {
+        return ESP_FAIL;
+    }
+
+    return ESP_OK;
+}
\ No newline at end of file
diff --git a/main/service/service_clock.h b/main/service/service_clock.h
new file mode 100644
index 0000000..7099eb1
--- /dev/null
+++ b/main/service/service_clock.h
@@ -0,0 +1,8 @@
+#ifndef SERVICE_CLOCK_H
+#define SERVICE_CLOCK_H
+
+#include "esp_system.h"
+
+esp_err_t service_clock_init(void);
+
+#endif
\ No newline at end of file
diff --git a/main/service/service_dht.c b/main/service/service_dht.c
index eebcdf3..40204bd 100644
--- a/main/service/service_dht.c
+++ b/main/service/service_dht.c
@@ -29,11 +29,11 @@ void dht_task(void *pvParameters) {
         }
 
         queue_item.item = IF_STANDBY_ITEM_TEMP,
-        snprintf(queue_item.payload, 16, "%.2f", result.temperature);
+        snprintf(queue_item.payload, IF_STANDBY_PAYLOAD_LENGTH, "%.2f", result.temperature);
         xQueueSendToBack(g_standby_screen_queue, &queue_item, 0);
 
         queue_item.item = IF_STANDBY_ITEM_HUMID;
-        snprintf(queue_item.payload, 16, "%.2f", result.humidity);
+        snprintf(queue_item.payload, IF_STANDBY_PAYLOAD_LENGTH, "%.2f", result.humidity);
         xQueueSendToBack(g_standby_screen_queue, &queue_item, 0);
 
         vTaskDelay(pdMS_TO_TICKS(30000));