diff --git a/RoomsService/src/main/java/fr/insa/arm/RoomsService/controller/RoomsServiceController.java b/RoomsService/src/main/java/fr/insa/arm/RoomsService/controller/RoomsServiceController.java
index e041c31..3c3b511 100644
--- a/RoomsService/src/main/java/fr/insa/arm/RoomsService/controller/RoomsServiceController.java
+++ b/RoomsService/src/main/java/fr/insa/arm/RoomsService/controller/RoomsServiceController.java
@@ -42,8 +42,8 @@ public class RoomsServiceController {
         return rooms.affectDevice(idRoom, type, idDevice);
     }
     
-    @DeleteMapping("/{id}/devices")
-    public boolean removeDevice(@PathVariable("id") int idRoom, @RequestParam String type, @RequestBody Integer idDevice) {
+    @DeleteMapping("/{id}/devices/{idDevice}")
+    public boolean removeDevice(@PathVariable("id") int idRoom, @RequestParam String type, @PathVariable("idDevice") Integer idDevice) {
         return rooms.removeDevice(idRoom, type, idDevice);
     }
 
@@ -57,14 +57,19 @@ public class RoomsServiceController {
         return rooms.getPersons(id);
     }
 
-    @PostMapping("/{id}/persons")
+    @PostMapping("/{id}/persons/add")
     public Integer addPersons(@PathVariable("id") int idRoom, @RequestBody Integer nbPersons) {
         return rooms.addPersons(idRoom, nbPersons);
     }
 
-    @DeleteMapping("/{id}/persons")
+    @PostMapping("/{id}/persons/remove")
     public Integer removePersons(@PathVariable("id") int idRoom, @RequestBody Integer nbPersons) {
         return rooms.removePersons(idRoom, nbPersons);
     }
 
+    @GetMapping("/{id}/elapsedTime")
+    public Long getElapsedTime(@PathVariable("id") int idRoom) {
+        return rooms.getElapsedTime(idRoom);
+    }
+
 }
\ No newline at end of file
diff --git a/RoomsService/src/main/java/fr/insa/arm/RoomsService/model/INSA.java b/RoomsService/src/main/java/fr/insa/arm/RoomsService/model/INSA.java
index 049f08d..3fdc6a7 100644
--- a/RoomsService/src/main/java/fr/insa/arm/RoomsService/model/INSA.java
+++ b/RoomsService/src/main/java/fr/insa/arm/RoomsService/model/INSA.java
@@ -53,15 +53,14 @@ public class INSA {
 	public Integer getPersons(int idRoom) {
 		Room room = rooms.get(idRoom);
 		if (room == null) return null;
-		else return room.countPeople;
+		else return room.getPersons();
 	}
 
 	public Integer addPersons(int idRoom, int nbPersons) {
 		Room room = rooms.get(idRoom);
 		if (room == null) return null;
 		else {
-			room.countPeople += nbPersons;
-			return room.countPeople;
+			return room.addPersons(nbPersons);
 		}
 	}
 
@@ -69,8 +68,16 @@ public class INSA {
 		Room room = rooms.get(idRoom);
 		if (room == null) return null;
 		else {
-			room.countPeople = Math.max(room.countPeople-nbPersons, 0); // Prevent having -1 person in a room
-			return room.countPeople;
+			return room.removePersons(nbPersons);
 		}
 	}
+
+	public Long getElapsedTime(int idRoom) {
+		Room room = rooms.get(idRoom);
+		if (room == null) return null;
+		else {
+			return room.getElapsedTime();
+		}
+	}
+
 }
diff --git a/RoomsService/src/main/java/fr/insa/arm/RoomsService/model/Room.java b/RoomsService/src/main/java/fr/insa/arm/RoomsService/model/Room.java
index 97f29be..16d97b2 100644
--- a/RoomsService/src/main/java/fr/insa/arm/RoomsService/model/Room.java
+++ b/RoomsService/src/main/java/fr/insa/arm/RoomsService/model/Room.java
@@ -3,7 +3,26 @@ package fr.insa.arm.RoomsService.model;
 import java.util.ArrayList;
 
 public class Room {
-	
+
+	private class MyTimer {
+		private long start = 0L;
+
+		public MyTimer() { }
+
+		public void start() {
+			start = System.currentTimeMillis();
+		}
+
+		public void stop() {
+			start = 0L;
+		}
+
+		public long getElapsedTime() {
+			long end = System.currentTimeMillis();
+			return end - start;
+		}
+	}
+
 	static int compteur = 0;
 	private final int id;
 	private final String name;
@@ -18,8 +37,9 @@ public class Room {
 	private final ArrayList<Integer> heatingActuator;
 	private final ArrayList<Integer> climActuator;
 	private final ArrayList<Integer> lightActuator;
-	public Integer countPeople = 0;
-	
+	private Integer countPeople = 0;
+	private final MyTimer timer = new MyTimer();
+
 	public Room(String name) {
 		this.id = Room.compteur;
 		Room.compteur++;
@@ -145,4 +165,27 @@ public class Room {
 		}
 	}
 
+	public Integer getPersons() {
+		return countPeople;
+	}
+
+	public Integer addPersons(int nbPersons) {
+		// If there was nobody before => starts the timer
+		if (countPeople == 0 && nbPersons > 0) timer.start();
+		countPeople = Math.max(countPeople+nbPersons, 0); // Prevent having -1 person in a room
+		return countPeople;
+	}
+
+	public Integer removePersons(int nbPersons) {
+		countPeople = Math.max(countPeople-nbPersons, 0); // Prevent having -1 person in a room
+		// If there is nobody left => stops the timer
+		if (countPeople == 0) timer.stop();
+		return countPeople;
+	}
+
+	public long getElapsedTime() {
+		if (countPeople > 0) return timer.getElapsedTime();
+		else return 0L;
+	}
+
 }