diff --git a/calculation.py b/calculation.py
index 7f61a1f..1fb4b38 100644
--- a/calculation.py
+++ b/calculation.py
@@ -1,4 +1,5 @@
 
+
 def hoursSpent(day_start, day_end, break_start, break_end):
     duration_whole = day_end - day_start
     print("duration_whole", duration_whole)
diff --git a/day.py b/day.py
index e28b3b0..3aa9545 100644
--- a/day.py
+++ b/day.py
@@ -47,15 +47,11 @@ class Day:
 
         self.date: str = datetime.now().date()
 
-        self.begin: datetime = datetime.__init__
-
-        self.end: datetime = datetime.__init__
-
-        self.begin_break: datetime = datetime.__init__
-
-        self.end_break: datetime = datetime.__init__
-
-        self.duration: datetime = datetime.__init__
+        self.begin = 0
+        self.end = 0
+        self.begin_break = 0
+        self.end_break = 0
+        self.duration = 0
 
         self.isDayStarted: bool = False
         self.isBreakDone: bool = False
@@ -63,7 +59,7 @@ class Day:
 
     def beginDay(self):
         '''Saves the time where a new day was started.'''
-        self.begin = datetime.now()
+        self.begin_break = datetime.now()
         self.isDayStarted = True
 
     def make_break(self):
@@ -74,7 +70,7 @@ class Day:
             raise AssertionError(
                 "You are already in break or have done your break already")
 
-        self.beingin_break = datetime.now()
+        self.begin = datetime.now()
         self.isInBreak = True
 
     def stop_break(self):
diff --git a/ui.py b/ui.py
index f41d72e..aaac0ab 100644
--- a/ui.py
+++ b/ui.py
@@ -19,32 +19,39 @@ class Application(tk.Frame):
         self.quit.pack(side="bottom")
 
         self.begin_day = tk.Button(
-            self, text="begin day", command=self.bd)
+            self, text="begin day", command=self.day_begin)
         self.begin_day.pack(side="left")
 
-        self.end_day = tk.Button(self, text="end day", command=self.ed)
+        self.end_day = tk.Button(self, text="end day", command=self.day_end)
         self.end_day.pack(side="right")
 
-        self.begin_pause = tk.Button(self, text="begin pause", command=self.mb)
+        self.begin_pause = tk.Button(
+            self, text="begin pause", command=self.make_brake)
         self.begin_pause.pack(side="left")
 
-        self.end_pause = tk.Button(self, text="end pause", command=self.go)
+        self.end_pause = tk.Button(
+            self, text="end pause", command=self.stop_break)
         self.end_pause.pack(side="right")
 
-    def bd(self):
+    def day_begin(self):
         self.day.beginDay()
         self.hi_there["text"] = "Started day"
 
-    def ed(self):
+    def day_end(self):
+        if not self.day.is_day_started():
+            '''change field to: du musst erst day starten'''
+            return
+
         self.day.endDay()
         self.hi_there["text"] = "Good Bye"
+        self.day = Day()
 
-    def mb(self):
+    def make_brake(self):
         self.day.make_break()
         self.hi_there["text"] = "Have a nice lunch"
 
-    def go(self):
-        self.day.go_on()
+    def stop_break(self):
+        self.day.stop_break()
         self.hi_there["text"] = "Welcome back"