notification about future voucher expiry date starts 7 days before expiry date

smash/web/views/notifications.py

@@ -171,8 +171,10 @@ def get_subjects_with_no_visit(user):
 
 
 def get_subjects_with_almost_expired_vouchers(user):
-    notification_min_date = get_today_midnight_date() + datetime.timedelta(days=14)
-    contact_attempt_min_date = get_today_midnight_date() - datetime.timedelta(days=14)
+    # if expiry date is in the next 7 days
+    notification_min_date = get_today_midnight_date() + datetime.timedelta(days=7)
+    # if last successful contact was over 7 days ago
+    contact_attempt_min_date = get_today_midnight_date() - datetime.timedelta(days=7)
     result = StudySubject.objects.filter(
         subject__dead=False,
         resigned=False,