diff --git a/pages/api/sequences.py b/pages/api/sequences.py
index 168ea77..2db6ef8 100644
--- a/pages/api/sequences.py
+++ b/pages/api/sequences.py
@@ -24,12 +24,16 @@
 import logging
 
 from django.db import IntegrityError
+from django.shortcuts import get_object_or_404
 from rest_framework import (response as api_response,
                             viewsets, status)
 from rest_framework.decorators import action
+from rest_framework.views import APIView
 
-from ..models import (Sequence, EnumeratedElements)
-from ..serializers import (SequenceSerializer, EnumeratedElementSerializer)
+from ..models import (Sequence, EnumeratedElements,
+   SequenceProgress, EnumeratedProgress, LiveEvent)
+from ..serializers import (SequenceSerializer,
+   EnumeratedElementSerializer, AttendanceInputSerializer)
 
 LOGGER = logging.getLogger(__name__)
 
@@ -275,8 +279,62 @@ def remove_element(self, request, slug=None, element_rank=None):
             try:
                 element = EnumeratedElements.objects.get(sequence=sequence, rank=element_rank)
                 element.delete()
-                return api_response.Response({'detail': 'element removed'}, status=status.HTTP_200_OK)
+                return api_response.Response(
+                    {'detail': 'element removed'}, status=status.HTTP_200_OK)
             except EnumeratedElements.DoesNotExist:
                 return api_response.Response({'detail': 'element not found in sequence'},
                                              status=status.HTTP_404_NOT_FOUND)
         return api_response.Response({'detail': 'Invalid rank'}, status=status.HTTP_400_BAD_REQUEST)
+
+
+class LiveEventAttendanceAPIView(APIView):
+    '''
+    Allows marking a user's attendance to a Live Event.
+
+    The user's EnumeratedProgress viewing duration for the event is updated to
+    meet the minimum viewing duration requirement of the associated EnumeratedElement.
+
+    **Tags**: attendance, live events
+    '''
+    def post(self, request, *args, **kwargs):
+        """
+        - **Mark a User's attendance at a Live Event**
+
+        .. code-block:: http
+
+            POST /api/sequences/{sequence}/{rank}/{username}/mark-attendance HTTP/1.1
+
+        Responds
+
+        .. code-block:: json
+
+            {
+                "detail": "Attendance marked successfully"
+            }
+
+        """
+
+        input_serializer = AttendanceInputSerializer(data=self.kwargs)
+        input_serializer.is_valid(raise_exception=True)
+
+        sequence = input_serializer.validated_data['sequence']
+        user = input_serializer.validated_data['username']
+        rank = input_serializer.validated_data['rank']
+
+        sequence_progress, _ = SequenceProgress.objects.get_or_create(
+            user=user, sequence=sequence)
+        enumerated_progress, _ = EnumeratedProgress.objects.get_or_create(
+            progress=sequence_progress, rank=rank)
+        enumerated_element = get_object_or_404(
+            EnumeratedElements, rank=rank, sequence=sequence)
+        page_element = enumerated_element.page_element
+        live_event = LiveEvent.objects.filter(element=page_element).first()
+
+        # We use if live_event to confirm the existence of the LiveEvent object
+        if live_event and enumerated_progress.viewing_duration <= enumerated_element.min_viewing_duration:
+            enumerated_progress.viewing_duration = enumerated_element.min_viewing_duration
+            enumerated_progress.save()
+            return api_response.Response(
+                {'detail': 'Attendance marked successfully'}, status=status.HTTP_200_OK)
+        return api_response.Response(
+            {'detail': 'Attendance not marked'}, status=status.HTTP_400_BAD_REQUEST)
diff --git a/pages/models.py b/pages/models.py
index f150367..f93efe4 100644
--- a/pages/models.py
+++ b/pages/models.py
@@ -462,7 +462,7 @@ class SequenceProgress(models.Model):
     user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
     extra = get_extra_field_class()(null=True, blank=True,
         help_text=_("Extra meta data (can be stringify JSON)"))
-    completion_date = models.DateTimeField(
+    completion_date = models.DateTimeField(blank=True, null=True,
         help_text=_("Time when the user completed the Sequence"))
 
     def __str__(self):
diff --git a/pages/serializers.py b/pages/serializers.py
index a4abb8b..293fb80 100644
--- a/pages/serializers.py
+++ b/pages/serializers.py
@@ -29,6 +29,7 @@
 from rest_framework import serializers
 from django.contrib.auth import get_user_model
 from django.db import transaction
+from django.shortcuts import get_object_or_404
 
 
 from . import settings
@@ -368,3 +369,18 @@ class EnumeratedProgressPingSerializer(serializers.ModelSerializer):
     class Meta:
         model = EnumeratedProgress
         fields = ('created_at', 'viewing_duration', 'last_ping_time')
+
+class AttendanceInputSerializer(serializers.Serializer):
+    """
+    Serializer to validate input to mark users' attendance
+    to a LiveEvent(LiveEventAttendanceAPIView)
+    """
+    sequence = serializers.SlugField()
+    username = serializers.CharField()
+    rank = serializers.IntegerField()
+
+    def validate_sequence(self, value):
+        return get_object_or_404(Sequence, slug=value)
+
+    def validate_username(self, value):
+        return get_object_or_404(get_user_model(), username=value)
diff --git a/pages/urls/api/progress.py b/pages/urls/api/progress.py
index 988ed10..c7feb15 100644
--- a/pages/urls/api/progress.py
+++ b/pages/urls/api/progress.py
@@ -27,7 +27,7 @@
 """
 
 from ...api.progress import EnumeratedProgressAPIView
-from django.urls import path
+from ...compat import path
 
 urlpatterns = [
     path('<slug:sequence>',
diff --git a/pages/urls/api/sequences.py b/pages/urls/api/sequences.py
index 247ede9..86f0b45 100644
--- a/pages/urls/api/sequences.py
+++ b/pages/urls/api/sequences.py
@@ -26,12 +26,17 @@
 API URLs for sequence objects
 """
 
-from ...api.sequences import (SequenceAPIView)
+from ...api.sequences import (SequenceAPIView, LiveEventAttendanceAPIView)
 from rest_framework.routers import DefaultRouter
 
+from ...compat import path
+
 router = DefaultRouter(trailing_slash=False)
 router.register(r'sequences',
                 SequenceAPIView,
                 basename='api_sequences')
 urlpatterns = [
+    path('sequences/<slug:sequence>/<int:rank>/<username>/mark-attendance',
+         LiveEventAttendanceAPIView.as_view(),
+         name='api_mark_attendance')
 ] + router.urls