diff --git a/app.py b/app.py
index c823aa0..ee921c0 100644
--- a/app.py
+++ b/app.py
@@ -47,28 +47,22 @@ def index():
         with open(log_path, 'a', encoding='utf-8') as f:
             from datetime import datetime as dt
             f.write(f"{dt.now().isoformat()} FUNC: {action}\n")
-        if action == 'tage':
+        if action == 'tage_werktage':
             active_idx = 0
             start = request.form.get('start1')
             end = request.form.get('end1')
+            is_werktage = request.form.get('werktage') in ('on', 'true', '1', True)
             try:
                 d1 = datetime.strptime(start, '%Y-%m-%d')
                 d2 = datetime.strptime(end, '%Y-%m-%d')
-                tage = abs((d2 - d1).days)
+                if is_werktage:
+                    if d1 > d2:
+                        d1, d2 = d2, d1
+                    tage = np.busday_count(d1.date(), (d2 + timedelta(days=1)).date())
+                else:
+                    tage = abs((d2 - d1).days)
             except Exception:
                 tage = 'Ungültige Eingabe'
-        elif action == 'werktage':
-            active_idx = 1
-            start = request.form.get('start2')
-            end = request.form.get('end2')
-            try:
-                d1 = datetime.strptime(start, '%Y-%m-%d')
-                d2 = datetime.strptime(end, '%Y-%m-%d')
-                if d1 > d2:
-                    d1, d2 = d2, d1
-                werktage = np.busday_count(d1.date(), (d2 + timedelta(days=1)).date())
-            except Exception:
-                werktage = 'Ungültige Eingabe'
         elif action == 'wochentag':
             active_idx = 2
             datum = request.form.get('datum3')
diff --git a/templates/index.html b/templates/index.html
index ed032b8..01dd943 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -55,7 +55,7 @@
                         <!-- Kalender mit Doppelpfeil -->
                         <svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg"><rect x="3" y="5" width="18" height="16" rx="4" fill="#fff" stroke="#2563eb" stroke-width="2"/><rect x="3" y="5" width="18" height="4" rx="2" fill="#2563eb"/><rect x="6" y="2" width="2" height="4" rx="1" fill="#2563eb"/><rect x="16" y="2" width="2" height="4" rx="1" fill="#2563eb"/><path d="M8 15h8M8 15l2-2M8 15l2 2M16 15l-2-2M16 15l-2 2" stroke="#2563eb" stroke-width="1.5" stroke-linecap="round"/></svg>
                     </span>
-                    Anzahl der Tage zwischen zwei Daten
+                    Anzahl der Tage/Werktage zwischen zwei Daten
                 </button>
                 <div class="accordion-content">
                     <form method="post">
@@ -71,39 +71,20 @@
                                 <button type="button" class="today-btn" onclick="setToday('end1')">Heute</button>
                             </span>
                         </label>
-                        <button name="action" value="tage" type="submit">Berechnen</button>
+                        <label style="display:flex;align-items:center;gap:0.5em;margin-top:0.7em;">
+                            <input type="checkbox" name="werktage" id="werktage" {% if request.form.get('werktage') %}checked{% endif %}>
+                            Nur Werktage
+                        </label>
+                        <button name="action" value="tage_werktage" type="submit">Berechnen</button>
                     </form>
                     {% if tage is not none %}
-                        <div class="result">Anzahl der Tage zwischen <b>{{ format_date(request.form.get('start1', '')) }}</b> und <b>{{ format_date(request.form.get('end1', '')) }}</b>: {{ tage }}</div>
-                    {% endif %}
-                </div>
-            </div>
-            <div class="accordion-item">
-                <button type="button" class="accordion-header header-werktage" onclick="openAccordion(1)">
-                    <span style="vertical-align:middle;display:inline-block;width:1.5em;">
-                        <!-- Kalender mit Mo-Fr Symbol -->
-                        <svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg"><rect x="3" y="5" width="18" height="16" rx="4" fill="#fff" stroke="#2563eb" stroke-width="2"/><rect x="3" y="5" width="18" height="4" rx="2" fill="#2563eb"/><rect x="6" y="2" width="2" height="4" rx="1" fill="#2563eb"/><rect x="16" y="2" width="2" height="4" rx="1" fill="#2563eb"/><text x="12" y="17" text-anchor="middle" font-size="8" font-family="Segoe UI, Arial, sans-serif" fill="#2563eb" font-weight="bold">Mo-Fr</text></svg>
-                    </span>
-                    Anzahl der Werktage zwischen zwei Daten
-                </button>
-                <div class="accordion-content">
-                    <form method="post">
-                        <label>Startdatum:<br>
-                            <span class="date-row">
-                                <input type="date" name="start2" id="start2">
-                                <button type="button" class="today-btn" onclick="setToday('start2')">Heute</button>
-                            </span>
-                        </label>
-                        <label>Enddatum:<br>
-                            <span class="date-row">
-                                <input type="date" name="end2" id="end2">
-                                <button type="button" class="today-btn" onclick="setToday('end2')">Heute</button>
-                            </span>
-                        </label>
-                        <button name="action" value="werktage" type="submit">Berechnen</button>
-                    </form>
-                    {% if werktage is not none %}
-                        <div class="result">Anzahl der Werktage zwischen <b>{{ format_date(request.form.get('start2', '')) }}</b> und <b>{{ format_date(request.form.get('end2', '')) }}</b>: {{ werktage }}</div>
+                        <div class="result">
+                            {% if request.form.get('werktage') %}
+                                Anzahl der Werktage zwischen <b>{{ format_date(request.form.get('start1', '')) }}</b> und <b>{{ format_date(request.form.get('end1', '')) }}</b>: {{ tage }}
+                            {% else %}
+                                Anzahl der Tage zwischen <b>{{ format_date(request.form.get('start1', '')) }}</b> und <b>{{ format_date(request.form.get('end1', '')) }}</b>: {{ tage }}
+                            {% endif %}
+                        </div>
                     {% endif %}
                 </div>
             </div>
diff --git a/test_app.py b/test_app.py
index 2d47c61..c7839a0 100644
--- a/test_app.py
+++ b/test_app.py
@@ -15,7 +15,7 @@ def test_homepage(client):
 
 def test_tage_berechnung(client):
     resp = client.post('/', data={
-        'action': 'tage',
+        'action': 'tage_werktage',
         'start1': '2024-01-01',
         'end1': '2024-01-10'
     })
@@ -27,16 +27,34 @@ def test_xss_protection(client):
     # Versuche ein Skript einzuschleusen
     xss = '<script>alert(1)</script>'
     resp = client.post('/', data={
-        'action': 'tage',
+        'action': 'tage_werktage',
         'start1': xss,
         'end1': '2024-01-10'
     })
     assert resp.status_code == 200
-    # Das Skript darf nicht im HTML erscheinen (sollte escaped sein)
+    # Das Skript darf nicht im HTML erscheinen
     assert b'<script>alert(1)</script>' not in resp.data
-    assert b'&lt;script&gt;alert(1)&lt;/script&gt;' in resp.data
+    # Es sollte eine Fehlermeldung erscheinen
+    html = resp.data.decode('utf-8')
+    assert 'Ungültige Eingabe' in html
 
 def test_stats_login_required(client):
     resp = client.get('/stats')
     assert resp.status_code == 200
-    assert b'Dashboard Login' in resp.data 
\ No newline at end of file
+    assert b'Dashboard Login' in resp.data 
+
+def test_werktage_berechnung(client):
+    from numpy import busday_count
+    from datetime import date, timedelta
+    start = '2024-01-01'
+    end = '2024-03-01'
+    expected = busday_count(date.fromisoformat(start), date.fromisoformat(end) + timedelta(days=1))
+    resp = client.post('/', data={
+        'action': 'tage_werktage',
+        'start1': start,
+        'end1': end,
+        'werktage': 'on'
+    })
+    assert resp.status_code == 200
+    assert b'Anzahl der Werktage' in resp.data
+    assert f': {expected}'.encode() in resp.data 
\ No newline at end of file