diff --git a/asmodee.py b/asmodee.py
index be760b4..052c74d 100755
--- a/asmodee.py
+++ b/asmodee.py
@@ -1044,6 +1044,23 @@ def horloge(room, event): # Gestion des horloges PBTA
 			# Place le niveau de l'horloge entre 0 et 6
 			nv = int(args[len(args)-1])
 			clock[room.room_id, ' '.join(args[0:-1])] = nv
+		elif (len(args) >= 2 and (args[len(args)-1][:1] == "+" or args[len(args)-1][:1] == "-")):
+			nv = 0
+			hor = ' '.join(args[0:-1]
+			if (room.room_id, hor in clock):
+				nv = clock[room.room_id, hor)]
+			val = 0
+			if (args[len(args)-1][1:].isnumeric()):
+				val = args[len(args)-1][1:]
+			if (args[len(args)-1][:1] == "+"):
+				nv = nv + val
+				if (nv > 6):
+					nv = 6
+			else:
+				nv = nv - val
+				if (nv < 0):
+					nv = 0
+			clock[room.room_id, hor)] = nv
 		elif (len(args) >= 2 and args[0] == "del"):
 			# Supprime une horloge
 			args.pop(0)