diff --git a/upstart-jobs/cron.nix b/upstart-jobs/cron.nix
index 847ca2728dc..e2212b4c575 100644
--- a/upstart-jobs/cron.nix
+++ b/upstart-jobs/cron.nix
@@ -43,6 +43,9 @@ in
     start on startup
     stop on shutdown
 
+    # Needed to interpret times in the local timezone.
+    env TZ=${config.time.timeZone}
+
     respawn ${pkgs.cron}/sbin/cron -n
   '';
 }