diff --git a/timetable.py b/timetable.py
index ce0136af6d8af2a0d157f34df59fc2e943e99eba..0b036c056d8d3578e2ba27839bf8446e45eb70be 100644
--- a/timetable.py
+++ b/timetable.py
@@ -8,7 +8,10 @@ def timetable():
 		kw=0
 	else:
 		kw=int(request.args['kw'])
-	start = date.today() - timedelta(days=date.today().weekday() -7*kw)
+	try:
+		start = date.today() - timedelta(days=date.today().weekday() -7*kw)
+	except:
+		start = date.today() - timedelta(days=date.today().weekday())
 	days = [{'date': start, 'lectures': [], 'atonce':0, 'index': 0 }]
 	earlieststart=time(23,59)
 	latestend=time(0,0)