diff --git a/atst/models/task_order.py b/atst/models/task_order.py
index 0e2d5ba2..ed0b394d 100644
--- a/atst/models/task_order.py
+++ b/atst/models/task_order.py
@@ -70,15 +70,11 @@ class TaskOrder(Base, mixins.TimestampsMixin):
 
     @property
     def start_date(self):
-        # TODO: fix task order -- reimplement using CLINs
-        # Faked for display purposes
-        return date.today()
+        return min(c.start_date for c in self.clins)
 
     @property
     def end_date(self):
-        # TODO: fix task order -- reimplement using CLINs
-        # Faked for display purposes
-        return date.today()
+        return max(c.end_date for c in self.clins)
 
     @property
     def days_to_expiration(self):
diff --git a/tests/factories.py b/tests/factories.py
index c7c64dc5..60bd76a9 100644
--- a/tests/factories.py
+++ b/tests/factories.py
@@ -293,7 +293,7 @@ class CLINFactory(Base):
     start_date = datetime.date.today()
     end_date = factory.LazyFunction(random_future_date)
     obligated_amount = random.randint(100, 999999)
-    jedi_clin_type = random.choice([e for e in clin.JEDICLINType])
+    jedi_clin_type = random.choice(list(clin.JEDICLINType))
 
 
 class NotificationRecipientFactory(Base):
diff --git a/tests/models/test_task_order.py b/tests/models/test_task_order.py
index d6ae9e1c..59d3beba 100644
--- a/tests/models/test_task_order.py
+++ b/tests/models/test_task_order.py
@@ -1,5 +1,6 @@
 from werkzeug.datastructures import FileStorage
-import pytest, datetime
+import pytest
+from datetime import date
 
 from atst.models import *
 from atst.models.clin import JEDICLINType
@@ -14,6 +15,38 @@ from tests.factories import (
 from tests.mocks import PDF_FILENAME
 
 
+class TestPeriodOfPerformance:
+    def test_period_of_performance_is_first_to_last_clin(self):
+        start_date = date(2019, 6, 6)
+        end_date = date(2020, 6, 6)
+
+        intermediate_start_date = date(2019, 7, 1)
+        intermediate_end_date = date(2020, 3, 1)
+
+        task_order = TaskOrderFactory.create(
+            clins=[
+                CLINFactory.create(
+                    start_date=intermediate_start_date, end_date=intermediate_end_date
+                ),
+                CLINFactory.create(
+                    start_date=start_date, end_date=intermediate_end_date
+                ),
+                CLINFactory.create(
+                    start_date=intermediate_start_date, end_date=intermediate_end_date
+                ),
+                CLINFactory.create(
+                    start_date=intermediate_start_date, end_date=end_date
+                ),
+                CLINFactory.create(
+                    start_date=intermediate_start_date, end_date=intermediate_end_date
+                ),
+            ]
+        )
+
+        assert task_order.start_date == start_date
+        assert task_order.end_date == end_date
+
+
 class TestTaskOrderStatus:
     @pytest.mark.skip(reason="Reimplement after adding CLINs")
     def test_started_status(self):