diff --git a/app/celery/nightly_tasks.py b/app/celery/nightly_tasks.py
index 97c1fa59a..73086fb40 100644
--- a/app/celery/nightly_tasks.py
+++ b/app/celery/nightly_tasks.py
@@ -150,11 +150,17 @@ def timeout_notifications():
 @notify_celery.task(name='send-daily-performance-platform-stats')
 @cronitor('send-daily-performance-platform-stats')
 @statsd(namespace="tasks")
-def send_daily_performance_platform_stats():
+def send_daily_performance_platform_stats(date=None):
+    # date is a string in the format of "YYYY-MM-DD"
+    if date is None:
+        date = (datetime.utcnow() - timedelta(days=1)).date()
+    else:
+        date = datetime.strptime(date, "%Y-%m-%d").date()
+
     if performance_platform_client.active:
-        yesterday = datetime.utcnow() - timedelta(days=1)
-        send_total_sent_notifications_to_performance_platform(bst_date=yesterday.date())
-        processing_time.send_processing_time_to_performance_platform()
+
+        send_total_sent_notifications_to_performance_platform(bst_date=date)
+        processing_time.send_processing_time_to_performance_platform(bst_date=date)
 
 
 def send_total_sent_notifications_to_performance_platform(bst_date):
diff --git a/app/performance_platform/processing_time.py b/app/performance_platform/processing_time.py
index ee2bfde1a..756c08bc1 100644
--- a/app/performance_platform/processing_time.py
+++ b/app/performance_platform/processing_time.py
@@ -1,16 +1,15 @@
-from datetime import datetime
+from datetime import timedelta
 
 from flask import current_app
 
-from app.utils import get_midnight_for_day_before, get_london_midnight_in_utc
+from app.utils import get_london_midnight_in_utc
 from app.dao.notifications_dao import dao_get_total_notifications_sent_per_day_for_performance_platform
 from app import performance_platform_client
 
 
-def send_processing_time_to_performance_platform():
-    today = datetime.utcnow()
-    start_time = get_midnight_for_day_before(today)
-    end_time = get_london_midnight_in_utc(today)
+def send_processing_time_to_performance_platform(bst_date):
+    start_time = get_london_midnight_in_utc(bst_date)
+    end_time = get_london_midnight_in_utc(bst_date + timedelta(days=1))
 
     send_processing_time_for_start_and_end(start_time, end_time)
 
diff --git a/tests/app/performance_platform/test_processing_time.py b/tests/app/performance_platform/test_processing_time.py
index 2458e866d..010c50097 100644
--- a/tests/app/performance_platform/test_processing_time.py
+++ b/tests/app/performance_platform/test_processing_time.py
@@ -1,4 +1,4 @@
-from datetime import datetime, timedelta
+from datetime import datetime, timedelta, date
 
 from freezegun import freeze_time
 
@@ -19,7 +19,7 @@ def test_send_processing_time_to_performance_platform_generates_correct_calls(mo
     create_notification(sample_template, created_at=created_at, sent_at=created_at + timedelta(seconds=15))
     create_notification(sample_template, created_at=datetime.utcnow() - timedelta(days=2))
 
-    send_processing_time_to_performance_platform()
+    send_processing_time_to_performance_platform(date(2016, 10, 17))
 
     send_mock.assert_any_call(datetime(2016, 10, 16, 23, 0), 'messages-total', 2)
     send_mock.assert_any_call(datetime(2016, 10, 16, 23, 0), 'messages-within-10-secs', 1)