diff --git a/code_polisseur/code_polisseur.ino b/code_polisseur/code_polisseur.ino
index 081dec7..4026dd4 100644
--- a/code_polisseur/code_polisseur.ino
+++ b/code_polisseur/code_polisseur.ino
@@ -17,7 +17,7 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
 #include <RotaryEncoder.h>
-#include "SevSeg.h"
+#include <SevSeg.h>
 #include <EveryTimer.h>
 #include <AccelStepper.h>
 
@@ -39,12 +39,12 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
 #define ROT_BUTT    11
 #define ROT_ENC_1   12
 #define ROT_ENC_2   13
+#define ROT_ENC_DIR -1
 
 #define STEPPER_STEP              10
 #define STEPPER_DIRECTION         0
 #define STEPPER_ENABLE            A5
 
-
 //SETTINGS
 #define SEVSEG_REFRESH            250   // Refresh rate in ms
 #define SEVSEG_BRIGHTNESS         100  // 100%, full brightness
@@ -80,6 +80,7 @@ bool leadingZeros = false; // Use 'true' if you'd like to keep the leading zeros
 long refresh_timer = 0;
 
 long countdown = 0;
+byte days = 0;
 byte hours = 0;
 byte minutes = 0;
 byte seconds = 0;
@@ -94,7 +95,7 @@ void countdown_callback() {
     if (countdown < 0) {
       countdown = 0;
     }
-    recalculate_HMS();
+    recalculate_DHMS();
     //Serial.println(countdown);
   }
   else {
@@ -116,8 +117,15 @@ void calculate_display_callback() {
     else {
       digitalWrite(SEVSEG_COLON, false);
     }
-    //Display HH:MM or MM:SS if there is less than 1h left
-    if (hours) {
+    //Display dd:HH if there is more than 1day left, HH:MM if less or MM:SS if there is less than 1h left
+    if (days) {
+      char dispBuf[] = "0d00";
+      dispBuf[0] = days + 48;
+      dispBuf[2] = (hours / 10) + 48;
+      dispBuf[3] = (hours % 10) + 48;
+      sevseg.setChars(dispBuf);
+    }
+    else if (hours) {
       sevseg.setNumber(100*hours+minutes);
     } else {
       sevseg.setNumber(100*minutes+seconds);
@@ -137,11 +145,12 @@ void update_encoder() {
   if (currVal != newVal) {
     currVal = newVal;
     if (mode == 0) {    // Mode 0 : speed setting
+      multiplier = 10;
       if (current_rpm >= 500) {
         multiplier = 100;   // default : 1 encoder step = +/- 10 step/min
                             // if speed > 500 : encoder step = +/- 100 step/min
       }
-      new_rpm += multiplier * dir;
+      new_rpm += multiplier * dir * ROT_ENC_DIR;
       if (new_rpm < STEPPER_MIN_SPEED) {
         new_rpm = STEPPER_MIN_SPEED;
       }
@@ -151,20 +160,27 @@ void update_encoder() {
     }
     if (mode == 1) {    //mode 1 : countdown setting
       multiplier = 60;  // default : 1 encoder step = +/- 1min
-                        // if countdown > 1h : encoder step = +/- 1h
-      if (countdown >= 3600) {
+                        // if countdown > 1h : encoder step = +/- 10min (600s)
+                        // if countdown > 1d : encoder step = +/- 1h (3600s)
+      if (countdown >= 86400) {
+        multiplier = 3600;
+      }
+      else if (countdown >= 3600) {
         multiplier = 600;
       }
-      countdown += multiplier * dir;
+      countdown += multiplier * dir * ROT_ENC_DIR;
+
+      //Min: 0 = no negative timer value
       if (countdown < 0) {
         countdown = 0;
       }
       
-      // Max: 86400s = 1 day
-      if (countdown >= 86400) {
-        countdown = 86399;
+      // Max: 864000s = 10 days
+      if (countdown >= 864000) {
+        countdown = 863999;
       }
-      recalculate_HMS();
+      
+      recalculate_DHMS();
     }
     Serial.print("RPM: ");
     Serial.print(new_rpm);
@@ -217,15 +233,23 @@ void update_stepper() {
   }
 }
 
-void recalculate_HMS() {
-  minutes = (countdown / 60) % 60;
-      if (countdown >= 3600) {
-        hours = countdown / 3600;  
-      }
-      else {
-        hours = 0;
-        seconds = countdown % 60;
-      }
+void recalculate_DHMS() {
+  //Calculate days, hours, minutes and seconds to be display
+  if (countdown >= 86400) {
+    days = countdown / 86400;
+    hours = (countdown % 86400) / 3600;  
+  }
+  else {
+    days = 0;
+    minutes = (countdown / 60) % 60;
+    if (countdown >= 3600) {
+      hours = countdown / 3600;  
+    }
+    else {
+      hours = 0;
+      seconds = countdown % 60;
+    }
+  }
 }
 
 void setup()
diff --git a/doc/README.md b/doc/README.md
new file mode 100644
index 0000000..8d1c8b6
--- /dev/null
+++ b/doc/README.md
@@ -0,0 +1 @@
+