diff --git a/src/App.tsx b/src/App.tsx
index 2fea46a..d5e2cda 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -10,6 +10,7 @@ interface DayRecord {
     breakMins: number;
     workedHrs: number;
     overtimeMinutes: number;
+    notWorking?: boolean;
 }
 
 type Records = Partial<Record<Workday, DayRecord>>;
@@ -17,7 +18,7 @@ type Records = Partial<Record<Workday, DayRecord>>;
 const STORAGE_KEY = 'workTrackerRecords';
 const CARRYOVER_KEY = 'workTrackerCarryover';
 
-const DEFAULT_RECORD: DayRecord = { start: '', end: '', breakMins: 0, workedHrs: 0, overtimeMinutes: 0 };
+const DEFAULT_RECORD: DayRecord = { start: '', end: '', breakMins: 0, workedHrs: 0, overtimeMinutes: 0, notWorking: false };
 
 const WEEKDAYS: Workday[] = ['Montag', 'Dienstag', 'Mittwoch', 'Donnerstag', 'Freitag'];
 
@@ -81,11 +82,16 @@ function App() {
     }
 
     const getWeeklyBalance = () => {
-        const days: Workday[] = ['Montag', 'Dienstag', 'Mittwoch', 'Donnerstag'];
-        return days.reduce((sum, day) => sum + (records[day]?.overtimeMinutes ?? 0), 0) + carryoverMinutes;
+        const days: Workday[] = ['Montag', 'Dienstag', 'Mittwoch', 'Donnerstag', 'Freitag'];
+        return days.reduce((sum, day) => {
+            const r = records[day];
+            if (!r || r.notWorking) return sum;
+            return sum + (r.overtimeMinutes ?? 0);
+        }, 0) + carryoverMinutes;
     }
 
     const getWorkEndTime = () => {
+        if (record.notWorking) return '-';
         const start = toMinutes(record.start);
         if (start === null) return '-';
         const balance = selectedDay === 'Freitag' ? getWeeklyBalance() : 0;
@@ -93,16 +99,25 @@ function App() {
     }
 
     const handleSave = () => {
+        if (record.notWorking) {
+            updateRecord({ workedHrs: 0, overtimeMinutes: 0 });
+            return;
+        }
         const hours = getHourDiff();
         updateRecord({ workedHrs: hours, overtimeMinutes: Math.round((hours - 8) * 60) });
     }
 
     const handleResetWorkdays = () => {
-        const totalOvertime = WEEKDAYS.reduce((sum, day) => sum + (records[day]?.overtimeMinutes ?? 0), 0) + carryoverMinutes;
+        const totalOvertime = WEEKDAYS.reduce((sum, day) => {
+            const r = records[day];
+            if (!r || r.notWorking) return sum;
+            return sum + (r.overtimeMinutes ?? 0);
+        }, 0) + carryoverMinutes;
         setCarryoverMinutes(totalOvertime);
         setRecords({});
     }
 
+
     const handleResetOvertime = () => {
         setCarryoverMinutes(0);
     }
@@ -111,16 +126,42 @@ function App() {
         <Center className={"my-auto"}>
             <Stack>
                 <SegmentedControl
-                    data={['Montag', 'Dienstag', 'Mittwoch', 'Donnerstag', 'Freitag']}
+                    data={WEEKDAYS.map((day) => ({
+                        value: day,
+                        label: (
+                            <span
+                                style={records[day]?.notWorking ? { color: 'var(--mantine-color-grape-4)' } : undefined}
+                            >
+                                {day}
+                            </span>
+                        ),
+                    }))}
+                    value={selectedDay}
                     onChange={(value) => setSelectedDay(value as Workday)}
                     className={"mt-2"}
                 />
+                <Button
+                    variant={"outline"}
+                    color={record.notWorking ? "grape" : "gray"}
+                    onClick={() => {
+                        const nowWorking = !record.notWorking;
+                        if (nowWorking) {
+                            updateRecord({ notWorking: true, start: '', end: '', breakMins: 0, workedHrs: 0, overtimeMinutes: 0 });
+                        } else {
+                            updateRecord({ notWorking: false });
+                        }
+                    }}
+                    fullWidth
+                >
+                    {record.notWorking ? "✓ Als Arbeitstag markieren" : "Nicht gearbeitet"}
+                </Button>
                 <TimePicker
                     value={record.start}
                     label={"Arbeitsbeginn"}
                     onChange={(value) => updateRecord({ start: value })}
                     format="24h"
                     clearable
+                    disabled={record.notWorking}
                 />
                 <TimePicker
                     value={record.end}
@@ -128,6 +169,7 @@ function App() {
                     onChange={(value) => updateRecord({ end: value })}
                     format="24h"
                     clearable
+                    disabled={record.notWorking}
                 />
                 <NumberInput
                     label={"Pause in Minuten"}
@@ -136,27 +178,34 @@ function App() {
                     onKeyDown={(event) => {
                         if (event.key === 'Enter') handleSave();
                     }}
+                    disabled={record.notWorking}
                 />
 
-                <Button onClick={handleSave}>
+                <Button onClick={handleSave} disabled={record.notWorking}>
                     Berechnen + Speichern
                 </Button>
 
-                <Text>Gearbeitete Stunden heute: {record.workedHrs.toFixed(2)}</Text>
+                {record.notWorking ? (
+                    <Text c={"grape"}>Heute nicht gearbeitet</Text>
+                ) : (
+                    <Text>Gearbeitete Stunden heute: {record.workedHrs.toFixed(2)}</Text>
+                )}
                 {carryoverMinutes !== 0 && (
                     <Text c={"blue"}>Übernommene Überstunden aus Vorwoche: {carryoverMinutes} Minuten</Text>
                 )}
                 {selectedDay === 'Freitag' && (
                     <Text c={"green"}>Übertragen aus Montag bis Donnerstag (inkl. Vorwoche): {getWeeklyBalance()} Minuten</Text>
                 )}
-                <Text>Wann du gehen kannst für 8 Stunden: {getWorkEndTime()}</Text>
-                {record.start && record.end && record.overtimeMinutes === 0 && (
+                {!record.notWorking && (
+                    <Text>Wann du gehen kannst für 8 Stunden: {getWorkEndTime()}</Text>
+                )}
+                {!record.notWorking && record.start && record.end && record.overtimeMinutes === 0 && (
                     <Text>Du hast genau 8 Stunden gearbeitet.</Text>
                 )}
-                {record.start && record.end && record.overtimeMinutes > 0 && (
+                {!record.notWorking && record.start && record.end && record.overtimeMinutes > 0 && (
                     <Text c="yellow">Überstunden: {record.overtimeMinutes} Minuten</Text>
                 )}
-                {record.start && record.end && record.overtimeMinutes < 0 && (
+                {!record.notWorking && record.start && record.end && record.overtimeMinutes < 0 && (
                     <Text c={"red"}>Fehlende Minuten für 8 Stunden: {-record.overtimeMinutes} Minuten</Text>
                 )}