diff --git a/timepiece/views.py b/timepiece/views.py
index <HASH>..<HASH> 100644
--- a/timepiece/views.py
+++ b/timepiece/views.py
@@ -562,7 +562,7 @@ def time_sheet_invoice_project(request, project_id, year, month):
     if not request.user.has_perm('timepiece.edit_person_time_sheet'):
         return HttpResponseForbidden('Forbidden')
     from_date = datetime.datetime(int(year), int(month), 1)
-    to_date = datetime.datetime(int(year), int(month) + 1, 1)
+    to_date = from_date + relativedelta(months=1)
     project = get_object_or_404(timepiece.Project, pk=project_id)
     initial = {
         'project': project,
refs #<I> - Fixed value error bug for December