diff --git a/.cron.yml b/.cron.yml
index c73446a44..28a2c70bf 100644
--- a/.cron.yml
+++ b/.cron.yml
@@ -17,7 +17,8 @@ jobs:
           type: decision-task
           treeherder-symbol: Nt
           target-tasks-method: nightly-test
-      when: []
+      when:
+        - {hour: 5, minute: 0}
     - name: fennec-production
       job:
           type: decision-task