diff --git a/reports/graphs.py b/reports/graphs.py
index c03a1900..754ed3da 100644
--- a/reports/graphs.py
+++ b/reports/graphs.py
@@ -58,6 +58,7 @@ def diaperchange_types(child):
 
 
 def sleep_times(child):
+    # TODO: Handle dates crossing over midnight!
     instances = Sleep.objects.filter(child=child).order_by('start')
     y_df = pd.DataFrame()
     text_df = pd.DataFrame()